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Posted to commits@subversion.apache.org by da...@apache.org on 2012/03/30 15:55:31 UTC

svn commit: r1307424 [3/11] - in /subversion/branches/revprop-packing: ./ build/ac-macros/ notes/ notes/directory-index/ notes/wc-ng/ subversion/bindings/javahl/ subversion/bindings/swig/python/svn/ subversion/bindings/swig/python/tests/ subversion/bin...

Modified: subversion/branches/revprop-packing/subversion/libsvn_client/merge.c
URL: http://svn.apache.org/viewvc/subversion/branches/revprop-packing/subversion/libsvn_client/merge.c?rev=1307424&r1=1307423&r2=1307424&view=diff
==============================================================================
--- subversion/branches/revprop-packing/subversion/libsvn_client/merge.c (original)
+++ subversion/branches/revprop-packing/subversion/libsvn_client/merge.c Fri Mar 30 13:55:26 2012
@@ -58,6 +58,7 @@
 #include "private/svn_mergeinfo_private.h"
 #include "private/svn_fspath.h"
 #include "private/svn_ra_private.h"
+#include "private/svn_client_private.h"
 
 #include "svn_private_config.h"
 
@@ -164,16 +165,24 @@ typedef struct url_uuid_t
   const char *uuid;
 } url_uuid_t;
 
+/* A location in a repository. */
+typedef struct repo_location_t
+{
+  url_uuid_t *repo;
+  svn_revnum_t rev;
+  const char *url;
+} repo_location_t;
+
 /* */
 typedef struct merge_source_t
 {
   /* "left" side URL and revision (inclusive iff youngest) */
-  const char *url1;
-  svn_revnum_t rev1;
+  /* The "repo" field is not currently initialized or used. */
+  repo_location_t loc1;
 
   /* "right" side URL and revision (inclusive iff youngest) */
-  const char *url2;
-  svn_revnum_t rev2;
+  /* The "repo" field is not currently initialized or used. */
+  repo_location_t loc2;
 
 } merge_source_t;
 
@@ -186,14 +195,10 @@ typedef struct merge_target_t
   /* Node kind of the WC node (at the start of the merge) */
   svn_node_kind_t kind;
 
-  /* URL of the node, or NULL if node is locally added */
-  const char *url;
-
-  /* Revision of the node, or NULL if node is locally added */
-  svn_revnum_t rev;
-
-  /* Repository root URL and UUID, even if node is locally added */
-  url_uuid_t repos_root;
+  /* The repository location of the base node of the target WC.  If the node
+   * is locally added, then URL & REV are NULL & SVN_INVALID_REVNUM.  REPO
+   * is always valid. */
+  repo_location_t loc;
 
 } merge_target_t;
 
@@ -331,12 +336,12 @@ check_repos_match(merge_cmd_baton_t *mer
                   const char *url,
                   apr_pool_t *scratch_pool)
 {
-  if (!svn_uri__is_ancestor(merge_b->target->repos_root.url, url))
+  if (!svn_uri__is_ancestor(merge_b->target->loc.repo->url, url))
     return svn_error_createf(
         SVN_ERR_UNSUPPORTED_FEATURE, NULL,
          _("Url '%s' of '%s' is not in repository '%s'"),
          url, svn_dirent_local_style(local_abspath, scratch_pool),
-         merge_b->target->repos_root.url);
+         merge_b->target->loc.repo->url);
 
   return SVN_NO_ERROR;
 }
@@ -527,21 +532,21 @@ make_conflict_versions(const svn_wc_conf
     const char *child = svn_dirent_skip_ancestor(merge_b->target->abspath,
                                                  victim_abspath);
     SVN_ERR_ASSERT(child != NULL);
-    left_url = svn_path_url_add_component2(merge_b->merge_source.url1,
+    left_url = svn_path_url_add_component2(merge_b->merge_source.loc1.url,
                                            child, merge_b->pool);
-    right_url = svn_path_url_add_component2(merge_b->merge_source.url2,
+    right_url = svn_path_url_add_component2(merge_b->merge_source.loc2.url,
                                             child, merge_b->pool);
   }
 
   *left = svn_wc_conflict_version_create(
             src_repos_url,
             svn_uri_skip_ancestor(src_repos_url, left_url, merge_b->pool),
-            merge_b->merge_source.rev1, node_kind, merge_b->pool);
+            merge_b->merge_source.loc1.rev, node_kind, merge_b->pool);
 
   *right = svn_wc_conflict_version_create(
              src_repos_url,
              svn_uri_skip_ancestor(src_repos_url, right_url, merge_b->pool),
-             merge_b->merge_source.rev2, node_kind, merge_b->pool);
+             merge_b->merge_source.loc2.rev, node_kind, merge_b->pool);
 
   return SVN_NO_ERROR;
 }
@@ -1171,7 +1176,7 @@ merge_props_changed(svn_wc_notify_state_
          http://svn.haxx.se/dev/archive-2008-09/0006.shtml.  If the
          merge sources are not ancestral then there is no concept of a
          'forward' or 'reverse' merge and we filter unconditionally. */
-      if (merge_b->merge_source.rev1 < merge_b->merge_source.rev2
+      if (merge_b->merge_source.loc1.rev < merge_b->merge_source.loc2.rev
           || !merge_b->sources_ancestral)
         SVN_ERR(filter_self_referential_mergeinfo(&props,
                                                   local_abspath,
@@ -1733,13 +1738,13 @@ merge_file_added(svn_wc_notify_state_t *
          merge-from-foreign-repository scenario) or wrong place in the
          right repository (in the same-repos scenario).  So we'll
          strip them.  (Is this a layering violation?)  */
-      if (svn_property_kind(NULL, prop->name) == svn_prop_wc_kind)
+      if (svn_property_kind2(prop->name) == svn_prop_wc_kind)
         continue;
 
       /* And in the foreign repository merge case, we only want
          regular properties. */
       if ((! merge_b->same_repos)
-          && (svn_property_kind(NULL, prop->name) != svn_prop_regular_kind))
+          && (svn_property_kind2(prop->name) != svn_prop_regular_kind))
         continue;
 
       /* Issue #3383: We don't want mergeinfo from a foreign repository. */
@@ -1799,7 +1804,7 @@ merge_file_added(svn_wc_notify_state_t *
                                            mine_abspath);
                 SVN_ERR_ASSERT(child != NULL);
                 copyfrom_url = svn_path_url_add_component2(
-                                             merge_b->merge_source.url2,
+                                             merge_b->merge_source.loc2.url,
                                              child, scratch_pool);
                 copyfrom_rev = rev2;
                 SVN_ERR(check_repos_match(merge_b, mine_abspath, copyfrom_url,
@@ -2194,7 +2199,7 @@ merge_dir_added(svn_wc_notify_state_t *s
      add. */
   if (merge_b->same_repos)
     {
-      copyfrom_url = svn_path_url_add_component2(merge_b->merge_source.url2,
+      copyfrom_url = svn_path_url_add_component2(merge_b->merge_source.loc2.url,
                                                  child, scratch_pool);
       copyfrom_rev = rev;
 
@@ -3356,7 +3361,7 @@ fix_deleted_subtree_ranges(const merge_s
 {
   int i;
   apr_pool_t *iterpool = svn_pool_create(scratch_pool);
-  svn_boolean_t is_rollback = source->rev2 < source->rev1;
+  svn_boolean_t is_rollback = source->loc2.rev < source->loc1.rev;
 
   /* CHILDREN_WITH_MERGEINFO is sorted in depth-first order, so
      start at index 1 to examine only subtrees. */
@@ -3430,12 +3435,13 @@ fix_deleted_subtree_ranges(const merge_s
           SVN_ERR_ASSERT(child_repos_src_path);
 
           child_primary_source_url =
-            svn_path_url_add_component2((source->rev1 < source->rev2)
-                                        ? source->url2 : source->url1,
+            svn_path_url_add_component2((source->loc1.rev < source->loc2.rev)
+                                        ? source->loc2.url : source->loc1.url,
                                         child_repos_src_path, iterpool);
 
           SVN_ERR(adjust_deleted_subtree_ranges(child, parent,
-                                                source->rev1, source->rev2,
+                                                source->loc1.rev,
+                                                source->loc2.rev,
                                                 child_primary_source_url,
                                                 ra_session,
                                                 merge_b->ctx, result_pool,
@@ -3476,8 +3482,8 @@ fix_deleted_subtree_ranges(const merge_s
    is older than START, then the base revision is used as the younger
    bound in place of START.
 
-   RA_SESSION is an open RA session to the repository in which SOURCE lives.
-   It may be temporarily reparented as needed by this function.
+   RA_SESSION is an RA session open to the repository in which TARGET_ABSPATH
+   lives.  It may be temporarily reparented as needed by this function.
 
    Allocate *RECORDED_MERGEINFO and *IMPLICIT_MERGEINFO in RESULT_POOL.
    Use SCRATCH_POOL for any temporary allocations. */
@@ -3508,9 +3514,8 @@ get_full_mergeinfo(svn_mergeinfo_t *reco
 
   if (implicit_mergeinfo)
     {
-      const char *repos_root;
-      const char *repos_relpath;
       svn_revnum_t target_rev;
+      const char *target_url;
 
       /* Assert that we have sane input. */
       SVN_ERR_ASSERT(SVN_IS_VALID_REVNUM(start) && SVN_IS_VALID_REVNUM(end)
@@ -3518,18 +3523,15 @@ get_full_mergeinfo(svn_mergeinfo_t *reco
 
       /* Retrieve the origin (original_*) of the node, or just the
          url if the node was not copied. */
-      SVN_ERR(svn_wc__node_get_origin(FALSE, &target_rev, &repos_relpath,
-                                      &repos_root, NULL, NULL,
-                                      ctx->wc_ctx, target_abspath, FALSE,
-                                      scratch_pool, scratch_pool));
-
-      if (! repos_relpath)
-        {
-          /* We've been asked to operate on a target which has no location
-           * in the repository. Either it's unversioned (but attempts to
-           * merge into unversioned targets should not get as far as here),
-           * or it is locally added, in which case the target's implicit
-           * mergeinfo is empty. */
+      SVN_ERR(svn_client__wc_node_get_origin(NULL, NULL,
+                                             &target_rev, &target_url,
+                                             target_abspath, ctx,
+                                             scratch_pool, scratch_pool));
+
+      if (! target_url)
+        {
+          /* We've been asked to operate on a locally added target, so its
+           * implicit mergeinfo is empty. */
           *implicit_mergeinfo = apr_hash_make(result_pool);
         }
       else if (target_rev <= end)
@@ -3540,11 +3542,6 @@ get_full_mergeinfo(svn_mergeinfo_t *reco
         }
       else
         {
-          const char *url;
-
-          url = svn_path_url_add_component2(repos_root, repos_relpath,
-                                            scratch_pool);
-
           /* Fetch so-called "implicit mergeinfo" (that is, natural
              history). */
 
@@ -3558,7 +3555,7 @@ get_full_mergeinfo(svn_mergeinfo_t *reco
           /* Fetch the implicit mergeinfo. */
           SVN_ERR(svn_client__get_history_as_mergeinfo(implicit_mergeinfo,
                                                        NULL,
-                                                       url, target_rev,
+                                                       target_url, target_rev,
                                                        start, end,
                                                        ra_session, ctx,
                                                        result_pool));
@@ -3570,7 +3567,7 @@ get_full_mergeinfo(svn_mergeinfo_t *reco
 
 /* Helper for ensure_implicit_mergeinfo().
 
-   PARENT, CHILD, REVISION1, REVISION2, RA_SESSION, and CTX
+   PARENT, CHILD, REVISION1, REVISION2 and CTX
    are all cascaded from the arguments of the same names in
    ensure_implicit_mergeinfo().  PARENT and CHILD must both exist, i.e.
    this function should never be called where CHILD is the merge target.
@@ -3580,6 +3577,9 @@ get_full_mergeinfo(svn_mergeinfo_t *reco
    Set CHILD->IMPLICIT_MERGEINFO to the mergeinfo inherited from
    PARENT->IMPLICIT_MERGEINFO.  CHILD->IMPLICIT_MERGEINFO is allocated
    in RESULT_POOL.
+
+   RA_SESSION is an RA session open to the repository that contains CHILD.
+   It may be temporarily reparented by this function.
    */
 static svn_error_t *
 inherit_implicit_mergeinfo_from_parent(svn_client__merge_path_t *parent,
@@ -3630,7 +3630,10 @@ inherit_implicit_mergeinfo_from_parent(s
    PARENT->IMPLICIT_MERGEINFO, otherwise contact the repository.  Use
    SCRATCH_POOL for all temporary allocations.
 
-   PARENT, CHILD, REVISION1, REVISION2, RA_SESSION, and
+   RA_SESSION is an RA session open to the repository that contains CHILD.
+   It may be temporarily reparented by this function.
+
+   PARENT, CHILD, REVISION1, REVISION2 and
    CTX are all cascaded from the arguments of the same name in
    filter_merged_revisions() and the same conditions for that function
    hold here. */
@@ -3986,8 +3989,8 @@ calculate_remaining_ranges(svn_client__m
                            apr_pool_t *scratch_pool)
 {
   const char *mergeinfo_path;
-  const char *primary_url = (source->rev1 < source->rev2)
-                            ? source->url2 : source->url1;
+  const char *primary_url = (source->loc1.rev < source->loc2.rev)
+                            ? source->loc2.url : source->loc1.url;
   svn_mergeinfo_t adjusted_target_mergeinfo = NULL;
   svn_revnum_t child_base_revision;
 
@@ -4027,7 +4030,7 @@ calculate_remaining_ranges(svn_client__m
      merged (or, in the case of reverse merges, ranges not yet merged). */
   SVN_ERR(filter_merged_revisions(parent, child, mergeinfo_path,
                                   adjusted_target_mergeinfo,
-                                  source->rev1, source->rev2,
+                                  source->loc1.rev, source->loc2.rev,
                                   child_inherits_implicit,
                                   ra_session, ctx, result_pool,
                                   scratch_pool));
@@ -4064,8 +4067,8 @@ calculate_remaining_ranges(svn_client__m
      can't have any "future" history. */
   if (SVN_IS_VALID_REVNUM(child_base_revision)
       && ((child->remaining_ranges)->nelts == 0) /* Inoperative merge */
-      && (source->rev2 < source->rev1)                 /* Reverse merge */
-      && (child_base_revision <= source->rev2))     /* From CHILD's future */
+      && (source->loc2.rev < source->loc1.rev)     /* Reverse merge */
+      && (child_base_revision <= source->loc2.rev))  /* From CHILD's future */
     {
       /* Hmmm, an inoperative reverse merge from the "future".  If it is
          from our own future return a helpful error. */
@@ -4073,7 +4076,9 @@ calculate_remaining_ranges(svn_client__m
       const char *start_url;
 
       err = svn_client__repos_location(&start_url,
-                                       ra_session, source->url1, source->rev1,
+                                       ra_session,
+                                       source->loc1.url,
+                                       source->loc1.rev,
                                        child_base_revision,
                                        ctx, scratch_pool, scratch_pool);
       if (err)
@@ -4136,10 +4141,10 @@ find_gaps_in_merge_source_history(svn_re
                                   apr_pool_t *scratch_pool)
 {
   svn_mergeinfo_t implicit_src_mergeinfo;
-  svn_revnum_t young_rev = MAX(source->rev1, source->rev2);
-  svn_revnum_t old_rev = MIN(source->rev1, source->rev2);
-  const char *primary_url = (source->rev1 < source->rev2)
-                            ? source->url2 : source->url1;
+  svn_revnum_t young_rev = MAX(source->loc1.rev, source->loc2.rev);
+  svn_revnum_t old_rev = MIN(source->loc1.rev, source->loc2.rev);
+  const char *primary_url = (source->loc1.rev < source->loc2.rev)
+                            ? source->loc2.url : source->loc1.url;
   const char *merge_src_fspath;
   apr_array_header_t *rangelist;
 
@@ -4188,7 +4193,7 @@ find_gaps_in_merge_source_history(svn_re
       /* As mentioned above, multiple gaps *shouldn't* be possible. */
       SVN_ERR_ASSERT(apr_hash_count(implicit_src_mergeinfo) == 1);
 
-      *gap_start = MIN(source->rev1, source->rev2);
+      *gap_start = MIN(source->loc1.rev, source->loc2.rev);
       *gap_end = (APR_ARRAY_IDX(rangelist,
                                 rangelist->nelts - 1,
                                 svn_merge_range_t *))->start;
@@ -4196,8 +4201,8 @@ find_gaps_in_merge_source_history(svn_re
   else if (apr_hash_count(implicit_src_mergeinfo) > 1) /* Rename */
     {
       apr_array_header_t *requested_rangelist =
-        svn_rangelist__initialize(MIN(source->rev1, source->rev2),
-                                  MAX(source->rev1, source->rev2),
+        svn_rangelist__initialize(MIN(source->loc1.rev, source->loc2.rev),
+                                  MAX(source->loc1.rev, source->loc2.rev),
                                   TRUE, scratch_pool);
       apr_array_header_t *implicit_rangelist =
         apr_array_make(scratch_pool, 2, sizeof(svn_merge_range_t *));
@@ -4286,8 +4291,10 @@ populate_remaining_ranges(apr_array_head
                                          NULL, /* child->inherited_mergeinfo */
                                          svn_mergeinfo_inherited, ra_session,
                                          child->abspath,
-                                         MAX(source->rev1, source->rev2),
-                                         MIN(source->rev1, source->rev2),
+                                         MAX(source->loc1.rev,
+                                             source->loc2.rev),
+                                         MIN(source->loc1.rev,
+                                             source->loc2.rev),
                                          merge_b->ctx, result_pool,
                                          iterpool));
             }
@@ -4308,13 +4315,14 @@ populate_remaining_ranges(apr_array_head
               child_inherits_implicit = (parent && !child->switched);
               SVN_ERR(ensure_implicit_mergeinfo(parent, child,
                                                 child_inherits_implicit,
-                                                source->rev1, source->rev2,
+                                                source->loc1.rev,
+                                                source->loc2.rev,
                                                 ra_session, merge_b->ctx,
                                                 result_pool, iterpool));
             }
 
-          child->remaining_ranges = svn_rangelist__initialize(source->rev1,
-                                                              source->rev2,
+          child->remaining_ranges = svn_rangelist__initialize(source->loc1.rev,
+                                                              source->loc2.rev,
                                                               TRUE,
                                                               result_pool);
         }
@@ -4366,10 +4374,10 @@ populate_remaining_ranges(apr_array_head
       child_repos_path = svn_dirent_skip_ancestor(merge_b->target->abspath,
                                                   child->abspath);
       SVN_ERR_ASSERT(child_repos_path != NULL);
-      child_source.url1 = svn_path_url_add_component2(source->url1, child_repos_path,
-                                                      iterpool);
-      child_source.url2 = svn_path_url_add_component2(source->url2, child_repos_path,
-                                                      iterpool);
+      child_source.loc1.url = svn_path_url_add_component2(
+                                source->loc1.url, child_repos_path, iterpool);
+      child_source.loc2.url = svn_path_url_add_component2(
+                                source->loc2.url, child_repos_path, iterpool);
 
       /* Get the explicit/inherited mergeinfo for CHILD.  If CHILD is the
          merge target then also get its implicit mergeinfo.  Otherwise defer
@@ -4382,8 +4390,8 @@ populate_remaining_ranges(apr_array_head
         &(child->inherited_mergeinfo),
         svn_mergeinfo_inherited, ra_session,
         child->abspath,
-        MAX(source->rev1, source->rev2),
-        MIN(source->rev1, source->rev2),
+        MAX(source->loc1.rev, source->loc2.rev),
+        MIN(source->loc1.rev, source->loc2.rev),
         merge_b->ctx, result_pool, iterpool));
 
       /* If CHILD isn't the merge target find its parent. */
@@ -4434,7 +4442,7 @@ populate_remaining_ranges(apr_array_head
 
           /* If this is a reverse merge reorder CHILD->REMAINING_RANGES
               so it will work with the svn_rangelist_* APIs below. */
-          if (source->rev1 > source->rev2)
+          if (source->loc1.rev > source->loc2.rev)
             SVN_ERR(svn_rangelist_reverse(child->remaining_ranges, iterpool));
 
           for (j = 0; j < child->remaining_ranges->nelts; j++)
@@ -4476,7 +4484,7 @@ populate_remaining_ranges(apr_array_head
                                              result_pool));
             }
 
-          if (source->rev1 > source->rev2) /* Reverse merge */
+          if (source->loc1.rev > source->loc2.rev) /* Reverse merge */
             SVN_ERR(svn_rangelist_reverse(child->remaining_ranges, iterpool));
         }
     }
@@ -4877,11 +4885,11 @@ drive_merge_report_editor(const char *ta
   svn_revnum_t target_start;
   svn_boolean_t honor_mergeinfo = HONOR_MERGEINFO(merge_b);
   const char *old_sess1_url, *old_sess2_url;
-  svn_boolean_t is_rollback = source->rev1 > source->rev2;
+  svn_boolean_t is_rollback = source->loc1.rev > source->loc2.rev;
 
   /* Start with a safe default starting revision for the editor and the
      merge target. */
-  target_start = source->rev1;
+  target_start = source->loc1.rev;
 
   /* If we are honoring mergeinfo the starting revision for the merge target
      might not be SOURCE->rev1, in fact the merge target might not need *any*
@@ -4907,7 +4915,7 @@ drive_merge_report_editor(const char *ta
       if (child->remaining_ranges->nelts == 0)
         {
           /* The merge target doesn't need anything merged. */
-          target_start = source->rev2;
+          target_start = source->loc2.rev;
         }
       else
         {
@@ -4918,11 +4926,11 @@ drive_merge_report_editor(const char *ta
           svn_merge_range_t *range =
             APR_ARRAY_IDX(child->remaining_ranges, 0,
                           svn_merge_range_t *);
-          if ((!is_rollback && range->start > source->rev2)
-              || (is_rollback && range->start < source->rev2))
+          if ((!is_rollback && range->start > source->loc2.rev)
+              || (is_rollback && range->start < source->loc2.rev))
             {
               /* Merge target's first remaining range doesn't intersect. */
-              target_start = source->rev2;
+              target_start = source->loc2.rev;
             }
           else
             {
@@ -4935,18 +4943,18 @@ drive_merge_report_editor(const char *ta
 
   SVN_ERR(svn_client__ensure_ra_session_url(&old_sess1_url,
                                             merge_b->ra_session1,
-                                            source->url1, scratch_pool));
+                                            source->loc1.url, scratch_pool));
   /* Temporarily point our second RA session to SOURCE->url1, too.  We use
      this to request individual file contents. */
   SVN_ERR(svn_client__ensure_ra_session_url(&old_sess2_url,
                                             merge_b->ra_session2,
-                                            source->url1, scratch_pool));
+                                            source->loc1.url, scratch_pool));
 
   /* Get the diff editor and a reporter with which to, ultimately,
      drive it. */
   SVN_ERR(svn_client__get_diff_editor(&diff_editor, &diff_edit_baton,
                                       depth,
-                                      merge_b->ra_session2, source->rev1,
+                                      merge_b->ra_session2, source->loc1.rev,
                                       FALSE /* walk_deleted_dirs */,
                                       TRUE /* text_deltas */,
                                       &merge_callbacks, merge_b,
@@ -4955,10 +4963,10 @@ drive_merge_report_editor(const char *ta
                                       notification_receiver, notify_b,
                                       scratch_pool));
   SVN_ERR(svn_ra_do_diff3(merge_b->ra_session1,
-                          &reporter, &report_baton, source->rev2,
+                          &reporter, &report_baton, source->loc2.rev,
                           "", depth, merge_b->ignore_ancestry,
                           TRUE,  /* text_deltas */
-                          source->url2, diff_editor, diff_edit_baton,
+                          source->loc2.url, diff_editor, diff_edit_baton,
                           scratch_pool));
 
   /* Drive the reporter. */
@@ -5003,8 +5011,8 @@ drive_merge_report_editor(const char *ta
             {
               range = APR_ARRAY_IDX(child->remaining_ranges, 0,
                                     svn_merge_range_t *);
-              if ((!is_rollback && range->start > source->rev2)
-                  || (is_rollback && range->start < source->rev2))
+              if ((!is_rollback && range->start > source->loc2.rev)
+                  || (is_rollback && range->start < source->loc2.rev))
                 {
                   /* This child's first remaining range comes after the range
                      we are currently merging, so skip it. We expect to get
@@ -5042,14 +5050,14 @@ drive_merge_report_editor(const char *ta
           SVN_ERR_ASSERT(child_repos_path);
 
           if ((child->remaining_ranges->nelts == 0)
-              || (is_rollback && (range->start < source->rev2))
-              || (!is_rollback && (range->start > source->rev2)))
+              || (is_rollback && (range->start < source->loc2.rev))
+              || (!is_rollback && (range->start > source->loc2.rev)))
             {
               /* Nothing to merge to this child.  We'll claim we have
                  it up to date so the server doesn't send us
                  anything. */
               SVN_ERR(reporter->set_path(report_baton, child_repos_path,
-                                         source->rev2, depth, FALSE,
+                                         source->loc2.rev, depth, FALSE,
                                          NULL, iterpool));
             }
           else
@@ -6193,8 +6201,8 @@ static int
 compare_merge_source_ts(const void *a,
                         const void *b)
 {
-  svn_revnum_t a_rev = ((const merge_source_t *)a)->rev1;
-  svn_revnum_t b_rev = ((const merge_source_t *)b)->rev1;
+  svn_revnum_t a_rev = ((const merge_source_t *)a)->loc1.rev;
+  svn_revnum_t b_rev = ((const merge_source_t *)b)->loc1.rev;
   if (a_rev == b_rev)
     return 0;
   return a_rev < b_rev ? 1 : -1;
@@ -6272,24 +6280,21 @@ combine_range_with_segments(apr_array_he
 
       /* Build our merge source structure. */
       merge_source = apr_pcalloc(pool, sizeof(*merge_source));
-      merge_source->url1 = svn_path_url_add_component2(source_root_url,
-                                                       path1,
-                                                       pool);
-      merge_source->url2 = svn_path_url_add_component2(source_root_url,
-                                                       segment->path,
-                                                       pool);
-      merge_source->rev1 = rev1;
-      merge_source->rev2 = MIN(segment->range_end, maxrev);
+      merge_source->loc1.url = svn_path_url_add_component2(source_root_url,
+                                                           path1,
+                                                           pool);
+      merge_source->loc2.url = svn_path_url_add_component2(source_root_url,
+                                                           segment->path,
+                                                           pool);
+      merge_source->loc1.rev = rev1;
+      merge_source->loc2.rev = MIN(segment->range_end, maxrev);
 
       /* If this is subtractive, reverse the whole calculation. */
       if (subtractive)
         {
-          svn_revnum_t tmprev = merge_source->rev1;
-          const char *tmpurl = merge_source->url1;
-          merge_source->rev1 = merge_source->rev2;
-          merge_source->url1 = merge_source->url2;
-          merge_source->rev2 = tmprev;
-          merge_source->url2 = tmpurl;
+          repo_location_t tmploc = merge_source->loc1;
+          merge_source->loc1 = merge_source->loc2;
+          merge_source->loc2 = tmploc;
         }
 
       APR_ARRAY_PUSH(merge_source_ts, merge_source_t *) = merge_source;
@@ -6636,23 +6641,23 @@ subrange_source(const merge_source_t *so
                 svn_revnum_t end_rev,
                 apr_pool_t *pool)
 {
-  svn_boolean_t is_rollback = (source->rev1 > source->rev2);
-  svn_boolean_t same_urls = (strcmp(source->url1, source->url2) == 0);
+  svn_boolean_t is_rollback = (source->loc1.rev > source->loc2.rev);
+  svn_boolean_t same_urls = (strcmp(source->loc1.url, source->loc2.url) == 0);
   merge_source_t *real_source = apr_palloc(pool, sizeof(*source));
 
-  real_source->url1 = source->url1;
-  real_source->rev1 = start_rev;
-  real_source->url2 = source->url2;
-  real_source->rev2 = end_rev;
+  real_source->loc1.url = source->loc1.url;
+  real_source->loc1.rev = start_rev;
+  real_source->loc2.url = source->loc2.url;
+  real_source->loc2.rev = end_rev;
   if (! same_urls)
     {
-      if (is_rollback && (end_rev != source->rev2))
+      if (is_rollback && (end_rev != source->loc2.rev))
         {
-          real_source->url2 = source->url1;
+          real_source->loc2.url = source->loc1.url;
         }
-      if ((! is_rollback) && (start_rev != source->rev1))
+      if ((! is_rollback) && (start_rev != source->loc1.rev))
         {
-          real_source->url1 = source->url2;
+          real_source->loc1.url = source->loc2.url;
         }
     }
   return real_source;
@@ -6693,8 +6698,8 @@ do_file_merge(svn_mergeinfo_catalog_t re
   svn_mergeinfo_t target_mergeinfo;
   svn_merge_range_t *conflicted_range = NULL;
   svn_boolean_t inherited = FALSE;
-  svn_boolean_t is_rollback = (source->rev1 > source->rev2);
-  const char *primary_url = is_rollback ? source->url1 : source->url2;
+  svn_boolean_t is_rollback = (source->loc1.rev > source->loc2.rev);
+  const char *primary_url = is_rollback ? source->loc1.url : source->loc2.url;
   svn_boolean_t honor_mergeinfo = HONOR_MERGEINFO(merge_b);
   svn_client__merge_path_t *merge_target = NULL;
   apr_pool_t *iterpool = svn_pool_create(scratch_pool);
@@ -6704,8 +6709,8 @@ do_file_merge(svn_mergeinfo_catalog_t re
   /* Note that this is a single-file merge. */
   notify_b->is_single_file_merge = TRUE;
 
-  range.start = source->rev1;
-  range.end = source->rev2;
+  range.start = source->loc1.rev;
+  range.end = source->loc2.rev;
   range.inheritable = TRUE;
   if (honor_mergeinfo)
     {
@@ -6718,8 +6723,8 @@ do_file_merge(svn_mergeinfo_catalog_t re
                                &(merge_target->implicit_mergeinfo),
                                &inherited, svn_mergeinfo_inherited,
                                merge_b->ra_session1, target_abspath,
-                               MAX(source->rev1, source->rev2),
-                               MIN(source->rev1, source->rev2),
+                               MAX(source->loc1.rev, source->loc2.rev),
+                               MIN(source->loc1.rev, source->loc2.rev),
                                ctx, scratch_pool, iterpool);
 
       if (err)
@@ -6803,11 +6808,13 @@ do_file_merge(svn_mergeinfo_catalog_t re
           real_source = subrange_source(source, r->start, r->end, iterpool);
           SVN_ERR(single_file_merge_get_file(&tmpfile1, &props1,
                                              merge_b->ra_session1,
-                                             real_source->url1, real_source->rev1,
+                                             real_source->loc1.url,
+                                             real_source->loc1.rev,
                                              target_abspath, iterpool));
           SVN_ERR(single_file_merge_get_file(&tmpfile2, &props2,
                                              merge_b->ra_session2,
-                                             real_source->url2, real_source->rev2,
+                                             real_source->loc2.url,
+                                             real_source->loc2.rev,
                                              target_abspath, iterpool));
 
           /* Discover any svn:mime-type values in the proplists */
@@ -7156,7 +7163,8 @@ do_mergeinfo_unaware_dir_merge(const mer
   svn_client__merge_path_t *item
     = svn_client__merge_path_create(target_dir_wcpath, pool);
 
-  item->remaining_ranges = svn_rangelist__initialize(source->rev1, source->rev2,
+  item->remaining_ranges = svn_rangelist__initialize(source->loc1.rev,
+                                                     source->loc2.rev,
                                                      TRUE, pool);
   APR_ARRAY_PUSH(notify_b->children_with_mergeinfo,
                  svn_client__merge_path_t *) = item;
@@ -7767,7 +7775,7 @@ record_mergeinfo_for_dir_merge(svn_merge
               svn_mergeinfo_t subtree_history_as_mergeinfo;
               apr_array_header_t *child_merge_src_rangelist;
               const char *subtree_mergeinfo_url =
-                svn_path_url_add_component2(merge_b->target->repos_root.url,
+                svn_path_url_add_component2(merge_b->target->loc.repo->url,
                                             child_merge_src_fspath + 1,
                                             iterpool);
 
@@ -7966,7 +7974,7 @@ record_mergeinfo_for_added_subtrees(
              take the intersection of the naive mergeinfo with
              MERGEINFO_PATH/rel_added_path's history. */
           added_path_mergeinfo_url =
-            svn_path_url_add_component2(merge_b->target->repos_root.url,
+            svn_path_url_add_component2(merge_b->target->loc.repo->url,
                                         added_path_mergeinfo_fspath + 1,
                                         iterpool);
           SVN_ERR(svn_client__get_history_as_mergeinfo(
@@ -8228,7 +8236,7 @@ remove_noop_subtree_ranges(const merge_s
 
 
   /* This function is only intended to work with forward merges. */
-  if (source->rev1 > source->rev2)
+  if (source->loc1.rev > source->loc2.rev)
     return SVN_NO_ERROR;
 
   /* Another easy out: There are no subtrees. */
@@ -8241,8 +8249,10 @@ remove_noop_subtree_ranges(const merge_s
 
   /* Given the requested merge of SOURCE->rev1:rev2 might there be any
      part of this range required for subtrees but not for the target? */
-  requested_ranges = svn_rangelist__initialize(MIN(source->rev1, source->rev2),
-                                               MAX(source->rev1, source->rev2),
+  requested_ranges = svn_rangelist__initialize(MIN(source->loc1.rev,
+                                                   source->loc2.rev),
+                                               MAX(source->loc1.rev,
+                                                   source->loc2.rev),
                                                TRUE, scratch_pool);
   SVN_ERR(svn_rangelist_remove(&subtree_gap_ranges,
                                root_child->remaining_ranges,
@@ -8296,11 +8306,12 @@ remove_noop_subtree_ranges(const merge_s
   SVN_ERR(svn_client__path_relative_to_root(
                     &(log_gap_baton.target_fspath), merge_b->ctx->wc_ctx,
                     merge_b->target->abspath,
-                    merge_b->target->repos_root.url, TRUE, NULL,
+                    merge_b->target->loc.repo->url, TRUE, NULL,
                     result_pool, scratch_pool));
   SVN_ERR(svn_client__path_relative_to_root(
                     &(log_gap_baton.source_fspath), merge_b->ctx->wc_ctx,
-                    source->url2, merge_b->target->repos_root.url, TRUE, NULL,
+                    source->loc2.url,
+                    merge_b->target->loc.repo->url, TRUE, NULL,
                     result_pool, scratch_pool));
   log_gap_baton.merged_ranges = apr_array_make(scratch_pool, 0,
                                                sizeof(svn_revnum_t *));
@@ -8417,8 +8428,8 @@ do_directory_merge(svn_mergeinfo_catalog
 
   svn_ra_session_t *ra_session;
   svn_client__merge_path_t *target_merge_path;
-  svn_boolean_t is_rollback = (source->rev1 > source->rev2);
-  const char *primary_url = is_rollback ? source->url1 : source->url2;
+  svn_boolean_t is_rollback = (source->loc1.rev > source->loc2.rev);
+  const char *primary_url = is_rollback ? source->loc1.url : source->loc2.url;
   svn_boolean_t honor_mergeinfo = HONOR_MERGEINFO(merge_b);
 
   /* Note that this is not a single-file merge. */
@@ -8468,8 +8479,8 @@ do_directory_merge(svn_mergeinfo_catalog
 
   /* Always start with a range which describes the most inclusive merge
      possible, i.e. SOURCE->rev1:rev2. */
-  range.start = source->rev1;
-  range.end = source->rev2;
+  range.start = source->loc1.rev;
+  range.end = source->loc2.rev;
   range.inheritable = TRUE;
 
   if (honor_mergeinfo && !merge_b->reintegrate_merge)
@@ -8915,14 +8926,14 @@ do_merge(apr_hash_t **modified_subtrees,
 
       /* Sanity check:  if our left- and right-side merge sources are
          the same, there's nothing to here. */
-      if ((strcmp(source->url1, source->url2) == 0)
-          && (source->rev1 == source->rev2))
+      if ((strcmp(source->loc1.url, source->loc2.url) == 0)
+          && (source->loc1.rev == source->loc2.rev))
         continue;
 
       /* Establish RA sessions to our URLs, reuse where possible. */
-      SVN_ERR(ensure_ra_session_url(&ra_session1, source->url1,
+      SVN_ERR(ensure_ra_session_url(&ra_session1, source->loc1.url,
                                     ctx, scratch_pool));
-      SVN_ERR(ensure_ra_session_url(&ra_session2, source->url2,
+      SVN_ERR(ensure_ra_session_url(&ra_session2, source->loc2.url,
                                     ctx, scratch_pool));
 
       /* Populate the portions of the merge context baton that need to
@@ -9059,13 +9070,15 @@ merge_cousins_and_supplement_mergeinfo(c
   SVN_ERR_ASSERT(svn_dirent_is_absolute(target->abspath));
 
   SVN_ERR(normalize_merge_sources_internal(
-            &remove_sources, source->url1, source->rev1,
-            svn_rangelist__initialize(source->rev1, yc_rev, TRUE, scratch_pool),
+            &remove_sources, source->loc1.url, source->loc1.rev,
+            svn_rangelist__initialize(source->loc1.rev, yc_rev, TRUE,
+                                      scratch_pool),
             URL1_ra_session, ctx, scratch_pool, subpool));
 
   SVN_ERR(normalize_merge_sources_internal(
-            &add_sources, source->url2, source->rev2,
-            svn_rangelist__initialize(yc_rev, source->rev2, TRUE, scratch_pool),
+            &add_sources, source->loc2.url, source->loc2.rev,
+            svn_rangelist__initialize(yc_rev, source->loc2.rev, TRUE,
+                                      scratch_pool),
             URL2_ra_session, ctx, scratch_pool, subpool));
 
   /* If this isn't a record-only merge, we'll first do a stupid
@@ -9250,45 +9263,82 @@ ensure_wc_path_has_repo_revision(const c
   return SVN_NO_ERROR;
 }
 
-/* Set *TARGET to a new, fully initialized, target description structure. */
+/* "Open" the target WC for a merge.  That means:
+ *   - find out its node kind
+ *   - find out its exact repository location
+ *   - check the WC for suitability (throw an error if unsuitable)
+ *
+ * Set *TARGET_P to a new, fully initialized, target description structure.
+ *
+ * ALLOW_MIXED_REV, ALLOW_LOCAL_MODS, ALLOW_SWITCHED_SUBTREES determine
+ * whether the WC is deemed suitable; see ensure_wc_is_suitable_merge_target()
+ * for details.
+ *
+ * If the node is locally added, the rev and URL will be null/invalid. Some
+ * kinds of merge can use such a target; others can't.
+ */
 static svn_error_t *
-target_node_location(merge_target_t **target_p,
-                     const char *wc_abspath,
-                     svn_client_ctx_t *ctx,
-                     apr_pool_t *result_pool,
-                     apr_pool_t *scratch_pool)
+open_target_wc(merge_target_t **target_p,
+               const char *wc_abspath,
+               svn_boolean_t allow_mixed_rev,
+               svn_boolean_t allow_local_mods,
+               svn_boolean_t allow_switched_subtrees,
+               svn_client_ctx_t *ctx,
+               apr_pool_t *result_pool,
+               apr_pool_t *scratch_pool)
 {
   merge_target_t *target = apr_palloc(result_pool, sizeof(*target));
-  const char *relpath;
 
-  target->abspath = wc_abspath;
+  target->abspath = apr_pstrdup(result_pool, wc_abspath);
+
   SVN_ERR(svn_wc_read_kind(&target->kind, ctx->wc_ctx, wc_abspath, FALSE,
                            scratch_pool));
-  SVN_ERR(svn_wc__node_get_origin(NULL /* is_copy */,
-                                  &target->rev, &relpath,
-                                  &target->repos_root.url,
-                                  &target->repos_root.uuid,
-                                  NULL, ctx->wc_ctx, wc_abspath,
-                                  FALSE /* scan_deleted */,
-                                  result_pool, scratch_pool));
-  if (target->repos_root.url && relpath)
-    {
-      target->url = svn_path_url_add_component2(target->repos_root.url,
-                                                relpath, result_pool);
-    }
-  else
-    {
-      target->url = NULL;
-      SVN_ERR(svn_client_get_repos_root(&target->repos_root.url,
-                                        &target->repos_root.uuid,
-                                        wc_abspath,
-                                        ctx, result_pool, scratch_pool));
-    }
+
+  target->loc.repo = apr_palloc(result_pool, sizeof(*target->loc.repo));
+  SVN_ERR(svn_client__wc_node_get_origin(&target->loc.repo->url,
+                                         &target->loc.repo->uuid,
+                                         &target->loc.rev, &target->loc.url,
+                                         wc_abspath, ctx,
+                                         result_pool, scratch_pool));
+
+  SVN_ERR(ensure_wc_is_suitable_merge_target(
+            wc_abspath, ctx,
+            allow_mixed_rev, allow_local_mods, allow_switched_subtrees,
+            scratch_pool));
 
   *target_p = target;
   return SVN_NO_ERROR;
 }
 
+/* Open an RA session to PATH_OR_URL at PEG_REVISION.  Set *RA_SESSION_P to
+ * the session and set *LOCATION_P to the resolved revision, URL and
+ * repository root.  Allocate the results in RESULT_POOL.  */
+static svn_error_t *
+open_source_session(repo_location_t **location_p,
+                    svn_ra_session_t **ra_session_p,
+                    const char *path_or_url,
+                    const svn_opt_revision_t *peg_revision,
+                    svn_client_ctx_t *ctx,
+                    apr_pool_t *result_pool,
+                    apr_pool_t *scratch_pool)
+{
+  repo_location_t *location = apr_palloc(result_pool, sizeof(*location));
+  svn_ra_session_t *ra_session;
+
+  SVN_ERR(svn_client__ra_session_from_path(
+            &ra_session, &location->rev, &location->url,
+            path_or_url, NULL, peg_revision, peg_revision,
+            ctx, result_pool));
+  location->repo = apr_palloc(result_pool, sizeof(*location->repo));
+  SVN_ERR(svn_ra_get_repos_root2(ra_session, &location->repo->url,
+                                 result_pool));
+  SVN_ERR(svn_ra_get_uuid2(ra_session, &location->repo->uuid, result_pool));
+
+  *location_p = location;
+  *ra_session_p = ra_session;
+  return SVN_NO_ERROR;
+}
+
 
 /*-----------------------------------------------------------------------*/
 
@@ -9312,9 +9362,9 @@ merge_locked(const char *source1,
              apr_pool_t *scratch_pool)
 {
   merge_target_t *target;
+  repo_location_t *source1_loc, *source2_loc;
   merge_source_t source;
   svn_boolean_t related = FALSE, ancestral = FALSE;
-  url_uuid_t source_repos_root, source_repos_root2;
   svn_ra_session_t *ra_session1, *ra_session2;
   apr_array_header_t *merge_sources;
   svn_error_t *err;
@@ -9329,53 +9379,40 @@ merge_locked(const char *source1,
      ancestor of the other -- just call svn_client_merge_peg3() with
      the appropriate args. */
 
-  SVN_ERR(target_node_location(&target, target_abspath,
-                               ctx, scratch_pool, scratch_pool));
-
-  /* Do not allow merges into mixed-revision working copies. */
-  SVN_ERR(ensure_wc_is_suitable_merge_target(target->abspath, ctx,
-                                             allow_mixed_rev, TRUE, TRUE,
-                                             scratch_pool));
+  SVN_ERR(open_target_wc(&target, target_abspath,
+                         allow_mixed_rev, TRUE, TRUE,
+                         ctx, scratch_pool, scratch_pool));
 
   /* Open RA sessions to both sides of our merge source, and resolve URLs
    * and revisions. */
   sesspool = svn_pool_create(scratch_pool);
-  SVN_ERR(svn_client__ra_session_from_path(&ra_session1,
-                                           &source.rev1, &source.url1,
-                                           source1, NULL, revision1, revision1,
-                                           ctx, sesspool));
-  SVN_ERR(svn_client__ra_session_from_path(&ra_session2,
-                                           &source.rev2, &source.url2,
-                                           source2, NULL, revision2, revision2,
-                                           ctx, sesspool));
-
-  SVN_ERR(svn_ra_get_repos_root2(ra_session1, &source_repos_root.url,
-                                 sesspool));
-  SVN_ERR(svn_ra_get_uuid2(ra_session1, &source_repos_root.uuid,
-                           scratch_pool));
-  SVN_ERR(svn_ra_get_repos_root2(ra_session2, &source_repos_root2.url,
-                                 sesspool));
-  SVN_ERR(svn_ra_get_uuid2(ra_session2, &source_repos_root2.uuid,
-                           scratch_pool));
+  SVN_ERR(open_source_session(&source1_loc, &ra_session1, source1, revision1,
+                              ctx, sesspool, scratch_pool));
+  source.loc1 = *source1_loc;
+  SVN_ERR(open_source_session(&source2_loc, &ra_session2, source2, revision2,
+                              ctx, sesspool, scratch_pool));
+  source.loc2 = *source2_loc;
 
   /* We can't do a diff between different repositories. */
   /* ### We should also insist that the root URLs of the two sources match,
    *     as we are only carrying around a single source-repos-root from now
    *     on, and URL calculations will go wrong if they differ.
    *     Alternatively, teach the code to cope with differing root URLs. */
-  SVN_ERR(check_same_repos(&source_repos_root, source.url1,
-                           &source_repos_root2, source.url2,
+  SVN_ERR(check_same_repos(source1_loc->repo, source.loc1.url,
+                           source2_loc->repo, source.loc2.url,
                            FALSE /* strict_urls */, scratch_pool));
 
   /* Do our working copy and sources come from the same repository? */
-  same_repos = is_same_repos(&target->repos_root, &source_repos_root,
+  same_repos = is_same_repos(target->loc.repo, source1_loc->repo,
                              TRUE /* strict_urls */);
 
   /* Unless we're ignoring ancestry, see if the two sources are related.  */
   if (! ignore_ancestry)
     SVN_ERR(svn_client__get_youngest_common_ancestor(NULL, &yc_url, &yc_rev,
-                                                     source.url1, source.rev1,
-                                                     source.url2, source.rev2,
+                                                     source.loc1.url,
+                                                     source.loc1.rev,
+                                                     source.loc2.url,
+                                                     source.loc2.rev,
                                                      ctx, scratch_pool));
 
   /* Check for a youngest common ancestor.  If we have one, we'll be
@@ -9402,22 +9439,26 @@ merge_locked(const char *source1,
 
       /* If the common ancestor matches the right side of our merge,
          then we only need to reverse-merge the left side. */
-      if ((strcmp(yc_url, source.url2) == 0) && (yc_rev == source.rev2))
+      if ((strcmp(yc_url, source.loc2.url) == 0)
+          && (yc_rev == source.loc2.rev))
         {
           ancestral = TRUE;
           SVN_ERR(normalize_merge_sources_internal(
-                    &merge_sources, source.url1, source.rev1,
-                    svn_rangelist__initialize(source.rev1, yc_rev, TRUE, scratch_pool),
+                    &merge_sources, source.loc1.url, source.loc1.rev,
+                    svn_rangelist__initialize(source.loc1.rev, yc_rev, TRUE,
+                                              scratch_pool),
                     ra_session1, ctx, scratch_pool, scratch_pool));
         }
       /* If the common ancestor matches the left side of our merge,
          then we only need to merge the right side. */
-      else if ((strcmp(yc_url, source.url1) == 0) && (yc_rev == source.rev1))
+      else if ((strcmp(yc_url, source.loc1.url) == 0)
+               && (yc_rev == source.loc1.rev))
         {
           ancestral = TRUE;
           SVN_ERR(normalize_merge_sources_internal(
-                    &merge_sources, source.url2, source.rev2,
-                    svn_rangelist__initialize(yc_rev, source.rev2, TRUE, scratch_pool),
+                    &merge_sources, source.loc2.url, source.loc2.rev,
+                    svn_rangelist__initialize(yc_rev, source.loc2.rev, TRUE,
+                                              scratch_pool),
                     ra_session2, ctx, scratch_pool, scratch_pool));
         }
       /* And otherwise, we need to do both: reverse merge the left
@@ -9946,15 +9987,12 @@ find_unmerged_mergeinfo_subroutine(svn_m
    reintegrate source and the reintegrate target.
 
    SOURCE_REPOS_REL_PATH is the path of the reintegrate source relative to
-   the root of the repository.  TARGET_REPOS_REL_PATH is the path of the
-   reintegrate target relative to the root of the repository.
+   the root of the repository.
 
-   TARGET_REV is the working revision the entire WC tree rooted at
-   TARGET_REPOS_REL_PATH is at.  SOURCE_REV is the peg revision of the
-   reintegrate source.
+   SOURCE_REV is the peg revision of the reintegrate source.
 
    SOURCE_RA_SESSION is a session opened to the SOURCE_REPOS_REL_PATH
-   and TARGET_RA_SESSION is open to TARGET_REPOS_REL_PATH.
+   and TARGET_RA_SESSION is open to TARGET->loc.url.
 
    For each entry in TARGET_HISTORY_HASH check that the history it
    represents is contained in either the explicit mergeinfo for the
@@ -9982,8 +10020,7 @@ find_unmerged_mergeinfo(svn_mergeinfo_ca
                         svn_mergeinfo_catalog_t source_catalog,
                         apr_hash_t *target_history_hash,
                         const char *source_repos_rel_path,
-                        const char *target_repos_rel_path,
-                        svn_revnum_t target_rev,
+                        const merge_target_t *target,
                         svn_revnum_t source_rev,
                         svn_ra_session_t *source_ra_session,
                         svn_ra_session_t *target_ra_session,
@@ -9991,16 +10028,19 @@ find_unmerged_mergeinfo(svn_mergeinfo_ca
                         apr_pool_t *result_pool,
                         apr_pool_t *scratch_pool)
 {
+  const char *target_repos_rel_path;
   const char *source_session_url;
-  const char *target_session_url;
   apr_hash_index_t *hi;
   svn_mergeinfo_catalog_t new_catalog = apr_hash_make(result_pool);
   apr_pool_t *iterpool = svn_pool_create(scratch_pool);
 
+  SVN_ERR(svn_client__path_relative_to_root(&target_repos_rel_path,
+                                            ctx->wc_ctx, target->abspath,
+                                            NULL, FALSE, NULL,
+                                            scratch_pool, scratch_pool));
+
   *youngest_merged_rev = SVN_INVALID_REVNUM;
 
-  SVN_ERR(svn_ra_get_session_url(target_ra_session, &target_session_url,
-                                 scratch_pool));
   SVN_ERR(svn_ra_get_session_url(source_ra_session, &source_session_url,
                                  scratch_pool));
 
@@ -10124,12 +10164,12 @@ find_unmerged_mergeinfo(svn_mergeinfo_ca
 
       source_url = svn_path_url_add_component2(source_session_url,
                                                path_rel_to_session, iterpool);
-      target_url = svn_path_url_add_component2(target_session_url,
+      target_url = svn_path_url_add_component2(target->loc.url,
                                                path_rel_to_session, iterpool);
       err = svn_client__get_history_as_mergeinfo(&target_history_as_mergeinfo,
                                                  NULL /* has_rev_zero_history */,
                                                  target_url,
-                                                 target_rev, target_rev,
+                                                 target->loc.rev, target->loc.rev,
                                                  SVN_INVALID_REVNUM,
                                                  target_ra_session,
                                                  ctx, iterpool);
@@ -10161,7 +10201,7 @@ find_unmerged_mergeinfo(svn_mergeinfo_ca
           /* ### Why looking at SOURCE_url at TARGET_rev? */
           SVN_ERR(find_unmerged_mergeinfo_subroutine(
                     &filtered_mergeinfo, target_history_as_mergeinfo,
-                    source_mergeinfo, source_url, target_rev,
+                    source_mergeinfo, source_url, target->loc.rev,
                     source_ra_session, ctx, scratch_pool, iterpool));
           if (apr_hash_count(filtered_mergeinfo))
             apr_hash_set(new_catalog,
@@ -10194,30 +10234,26 @@ find_unmerged_mergeinfo(svn_mergeinfo_ca
    merge actually performs.  If no merge should be performed, set
    *URL_LEFT to NULL and *REV_LEFT to SVN_INVALID_REVNUM.
 
-   TARGET_ABSPATH is the absolute working copy path of the reintegrate
+   TARGET->abspath is the absolute working copy path of the reintegrate
    merge.
 
-   TARGET_REPOS_REL_PATH is the path of TARGET_ABSPATH relative to
-   the root of the repository.  SOURCE_REPOS_REL_PATH is the path of the
-   reintegrate source relative to the root of the repository.
+   SOURCE_LOC is the reintegrate source.
 
    SUBTREES_WITH_MERGEINFO is a hash of (const char *) absolute paths mapped
    to (svn_mergeinfo_t *) mergeinfo values for each working copy path with
-   explicit mergeinfo in TARGET_ABSPATH.  Actually we only need to know the
+   explicit mergeinfo in TARGET->abspath.  Actually we only need to know the
    paths, not the mergeinfo.
 
-   TARGET_REV is the working revision the entire WC tree rooted at
-   TARGET_REPOS_REL_PATH is at.  SOURCE_REV is the peg revision of the
-   reintegrate source.
+   TARGET->loc.rev is the working revision the entire WC tree rooted at
+   TARGET is at.
 
    Populate *UNMERGED_TO_SOURCE_CATALOG with the mergeinfo describing what
-   parts of TARGET_REPOS_REL_PATH@TARGET_REV have not been merged to
-   SOURCE_REPOS_REL_PATH@SOURCE_REV, up to the youngest revision ever merged
-   from the TARGET_ABSPATH to the source if such exists, see doc string for
-   find_unmerged_mergeinfo().
+   parts of TARGET->loc have not been merged to SOURCE_LOC, up to the
+   youngest revision ever merged from the TARGET->abspath to the source if
+   such exists, see doc string for find_unmerged_mergeinfo().
 
-   SOURCE_RA_SESSION is a session opened to the SOURCE_REPOS_REL_PATH
-   and TARGET_RA_SESSION is open to TARGET_REPOS_REL_PATH.
+   SOURCE_RA_SESSION is a session opened to the SOURCE_LOC
+   and TARGET_RA_SESSION is open to TARGET->loc.url.
 
    *URL_LEFT, *MERGED_TO_SOURCE_CATALOG , and *UNMERGED_TO_SOURCE_CATALOG are
    allocated in RESULT_POOL.  SCRATCH_POOL is used for all temporary
@@ -10227,20 +10263,15 @@ calculate_left_hand_side(const char **ur
                          svn_revnum_t *rev_left,
                          svn_mergeinfo_t *merged_to_source_catalog,
                          svn_mergeinfo_t *unmerged_to_source_catalog,
-                         const char *target_abspath,
-                         const char *target_repos_rel_path,
+                         const merge_target_t *target,
                          apr_hash_t *subtrees_with_mergeinfo,
-                         svn_revnum_t target_rev,
-                         const char *source_repos_rel_path,
-                         const char *source_repos_root,
-                         svn_revnum_t source_rev,
+                         const repo_location_t *source_loc,
                          svn_ra_session_t *source_ra_session,
                          svn_ra_session_t *target_ra_session,
                          svn_client_ctx_t *ctx,
                          apr_pool_t *result_pool,
                          apr_pool_t *scratch_pool)
 {
-  const char *target_repos_root_url = source_repos_root;  /* necessarily */
   svn_mergeinfo_catalog_t mergeinfo_catalog, unmerged_catalog;
   apr_array_header_t *source_repos_rel_path_as_array
     = apr_array_make(scratch_pool, 1, sizeof(const char *));
@@ -10251,8 +10282,7 @@ calculate_left_hand_side(const char **ur
   svn_revnum_t youngest_merged_rev;
   const char *yc_ancestor_url;
   svn_revnum_t yc_ancestor_rev;
-  const char *source_url;
-  const char *target_url;
+  const char *source_repos_rel_path;
 
   /* Initialize our return variables. */
   *url_left = NULL;
@@ -10262,9 +10292,9 @@ calculate_left_hand_side(const char **ur
      contained within SUBTREES_WITH_MERGEINFO.  If this is the case then
      add a dummy item for TARGET_ABSPATH so we get its history (i.e. implicit
      mergeinfo) below.  */
-  if (!apr_hash_get(subtrees_with_mergeinfo, target_abspath,
+  if (!apr_hash_get(subtrees_with_mergeinfo, target->abspath,
                     APR_HASH_KEY_STRING))
-    apr_hash_set(subtrees_with_mergeinfo, target_abspath,
+    apr_hash_set(subtrees_with_mergeinfo, target->abspath,
                  APR_HASH_KEY_STRING, apr_hash_make(result_pool));
 
   /* Get the history segments (as mergeinfo) for TARGET_ABSPATH and any of
@@ -10287,12 +10317,12 @@ calculate_left_hand_side(const char **ur
                                                 NULL, FALSE,
                                                 NULL, scratch_pool,
                                                 iterpool));
-      url = svn_path_url_add_component2(target_repos_root_url,
+      url = svn_path_url_add_component2(target->loc.repo->url,
                                         path_rel_to_root, iterpool);
       SVN_ERR(svn_client__get_history_as_mergeinfo(&target_history_as_mergeinfo,
                                                    NULL /* has_rev_zero_hist */,
                                                    url,
-                                                   target_rev, target_rev,
+                                                   target->loc.rev, target->loc.rev,
                                                    SVN_INVALID_REVNUM,
                                                    target_ra_session,
                                                    ctx, scratch_pool));
@@ -10305,27 +10335,21 @@ calculate_left_hand_side(const char **ur
   /* Check that SOURCE_URL@SOURCE_REV and TARGET_URL@TARGET_REV are
      actually related, we can't reintegrate if they are not.  Also
      get an initial value for YC_ANCESTOR_REV. */
-  source_url = svn_path_url_add_component2(source_repos_root,
-                                           source_repos_rel_path,
-                                           iterpool);
-  target_url = svn_path_url_add_component2(source_repos_root,
-                                           target_repos_rel_path,
-                                           iterpool);
   SVN_ERR(svn_client__get_youngest_common_ancestor(NULL, &yc_ancestor_url,
                                                    &yc_ancestor_rev,
-                                                   source_url, source_rev,
-                                                   target_url, target_rev,
+                                                   source_loc->url, source_loc->rev,
+                                                   target->loc.url, target->loc.rev,
                                                    ctx, iterpool));
   if (!(yc_ancestor_url && SVN_IS_VALID_REVNUM(yc_ancestor_rev)))
     return svn_error_createf(SVN_ERR_CLIENT_NOT_READY_TO_MERGE, NULL,
                              _("'%s@%ld' must be ancestrally related to "
-                               "'%s@%ld'"), source_url, source_rev,
-                             target_url, target_rev);
+                               "'%s@%ld'"), source_loc->url, source_loc->rev,
+                             target->loc.url, target->loc.rev);
 
   /* If the source revision is the same as the youngest common
      revision, then there can't possibly be any unmerged revisions
      that we need to apply to target. */
-  if (source_rev == yc_ancestor_rev)
+  if (source_loc->rev == yc_ancestor_rev)
     {
       svn_pool_destroy(iterpool);
       return SVN_NO_ERROR;
@@ -10335,10 +10359,12 @@ calculate_left_hand_side(const char **ur
      with differing explicit mergeinfo. */
   APR_ARRAY_PUSH(source_repos_rel_path_as_array, const char *) = "";
   SVN_ERR(svn_ra_get_mergeinfo(source_ra_session, &mergeinfo_catalog,
-                               source_repos_rel_path_as_array, source_rev,
+                               source_repos_rel_path_as_array, source_loc->rev,
                                svn_mergeinfo_inherited,
                                TRUE, iterpool));
 
+  source_repos_rel_path = svn_uri_skip_ancestor(source_loc->repo->url,
+                                                source_loc->url, scratch_pool);
   if (mergeinfo_catalog)
     SVN_ERR(svn_mergeinfo__add_prefix_to_catalog(&mergeinfo_catalog,
                                                  mergeinfo_catalog,
@@ -10360,9 +10386,8 @@ calculate_left_hand_side(const char **ur
                                   mergeinfo_catalog,
                                   target_history_hash,
                                   source_repos_rel_path,
-                                  target_repos_rel_path,
-                                  target_rev,
-                                  source_rev,
+                                  target,
+                                  source_loc->rev,
                                   source_ra_session,
                                   target_ra_session,
                                   ctx,
@@ -10387,7 +10412,7 @@ calculate_left_hand_side(const char **ur
          *URL_LEFT and *REV_LEFT to cover the youngest part of this range. */
       *rev_left = youngest_merged_rev;
       SVN_ERR(svn_client__repos_location(url_left, target_ra_session,
-                                         target_url, target_rev,
+                                         target->loc.url, target->loc.rev,
                                          youngest_merged_rev,
                                          ctx, result_pool, iterpool));
     }
@@ -10396,87 +10421,55 @@ calculate_left_hand_side(const char **ur
   return SVN_NO_ERROR;
 }
 
-/* The body of svn_client_find_reintegrate_merge(), which see for details. */
+/* Determine the URLs and revisions needed to perform a reintegrate merge
+ * from SOURCE_PATH_OR_URL at SOURCE_PEG_REVISION into the working
+ * copy at TARGET.
+ *
+ * SOURCE_RA_SESSION and TARGET_RA_SESSION are RA sessions opened to the
+ * source and target branches respectively.
+ *
+ * Set *SOURCE_P to
+ * the source-left and source-right locations of the required merge.  Set
+ * *YC_ANCESTOR_REV_P to the revision number of the youngest ancestor.
+ * Any of these output pointers may be NULL if not wanted.
+ *
+ * See svn_client_find_reintegrate_merge() for other details.
+ */
 static svn_error_t *
-find_reintegrate_merge(svn_ra_session_t **target_ra_session_p,
-                       svn_ra_session_t **source_ra_session_p,
-                       merge_source_t **source_p,
+find_reintegrate_merge(merge_source_t **source_p,
                        svn_revnum_t *yc_ancestor_rev_p,
-                       const char *source_path_or_url,
-                       const svn_opt_revision_t *source_peg_revision,
-                       const char *target_abspath,
+                       svn_ra_session_t *source_ra_session,
+                       const repo_location_t *source_loc,
+                       svn_ra_session_t *target_ra_session,
+                       const merge_target_t *target,
                        svn_client_ctx_t *ctx,
                        apr_pool_t *result_pool,
                        apr_pool_t *scratch_pool)
 {
-  url_uuid_t source_repos_root;
-  svn_ra_session_t *target_ra_session;
-  svn_ra_session_t *source_ra_session;
-  const char *source_repos_rel_path, *target_repos_rel_path;
   const char *yc_ancestor_relpath;
   svn_revnum_t yc_ancestor_rev;
-  merge_target_t *target;
   merge_source_t source;
   svn_mergeinfo_t unmerged_to_source_mergeinfo_catalog;
   svn_mergeinfo_t merged_to_source_mergeinfo_catalog;
   svn_error_t *err;
   apr_hash_t *subtrees_with_mergeinfo;
 
-  /* Make sure we're dealing with a real URL. */
-  SVN_ERR(svn_client_url_from_path2(&source.url2, source_path_or_url, ctx,
-                                    scratch_pool, scratch_pool));
-  if (! source.url2)
-    return svn_error_createf(SVN_ERR_ENTRY_MISSING_URL, NULL,
-                             _("'%s' has no URL"),
-                             svn_dirent_local_style(source_path_or_url,
-                                                    scratch_pool));
-
-  SVN_ERR(target_node_location(&target, target_abspath,
-                               ctx, scratch_pool, scratch_pool));
-
-  /* Determine the source's repository root URL. */
-  SVN_ERR(svn_client_get_repos_root(&source_repos_root.url,
-                                    &source_repos_root.uuid, source.url2,
-                                    ctx, scratch_pool, scratch_pool));
-
-  /* source_repos_root and target->repos_root are required to be the same,
-     as mergeinfo doesn't come into play for cross-repository merging. */
-  SVN_ERR(check_same_repos(&source_repos_root,
-                           svn_dirent_local_style(source_path_or_url,
-                                                  scratch_pool),
-                           &target->repos_root,
-                           svn_dirent_local_style(target_abspath, scratch_pool),
-                           TRUE /* strict_urls */, scratch_pool));
-
-  /* A reintegrate merge requires the merge target to reflect a subtree
-   * of the repository as found at a single revision. */
-  SVN_ERR(ensure_wc_is_suitable_merge_target(target_abspath, ctx,
-                                             FALSE, FALSE, FALSE,
-                                             scratch_pool));
-
   /* As the WC tree is "pure", use its last-updated-to revision as
      the default revision for the left side of our merge, since that's
      what the repository sub-tree is required to be up to date with
      (with regard to the WC). */
-  source.rev1 = target->rev;
-
-  source_repos_rel_path = svn_uri_skip_ancestor(target->repos_root.url, source.url2,
-                                                scratch_pool);
-  SVN_ERR(svn_client__path_relative_to_root(&target_repos_rel_path,
-                                            ctx->wc_ctx, target_abspath,
-                                            NULL, FALSE, NULL,
-                                            scratch_pool, scratch_pool));
+  /* ### Bogus/obsolete comment? */
 
   /* Can't reintegrate to or from the root of the repository. */
-  if (svn_path_is_empty(source_repos_rel_path)
-      || svn_path_is_empty(target_repos_rel_path))
+  if (strcmp(source_loc->url, source_loc->repo->url) == 0
+      || strcmp(target->loc.url, target->loc.repo->url) == 0)
     return svn_error_createf(SVN_ERR_CLIENT_NOT_READY_TO_MERGE, NULL,
                              _("Neither the reintegrate source nor target "
                                "can be the root of the repository"));
 
   /* Find all the subtrees in TARGET_WCPATH that have explicit mergeinfo. */
   err = get_wc_explicit_mergeinfo_catalog(&subtrees_with_mergeinfo,
-                                          target_abspath, svn_depth_infinity,
+                                          target->abspath, svn_depth_infinity,
                                           ctx, scratch_pool, scratch_pool);
   /* Issue #3896: If invalid mergeinfo in the reintegrate target
      prevents us from proceeding, then raise the best error possible. */
@@ -10484,26 +10477,12 @@ find_reintegrate_merge(svn_ra_session_t 
     err = svn_error_quick_wrap(err, _("Reintegrate merge not possible"));
   SVN_ERR(err);
 
-  /* Open two RA sessions, one to our source and one to our target. */
-  SVN_ERR(svn_client__ra_session_from_path(&source_ra_session, &source.rev2, &source.url2,
-                                           source.url2, NULL, source_peg_revision,
-                                           source_peg_revision,
-                                           ctx, result_pool));
-  SVN_ERR(svn_client__open_ra_session_internal(&target_ra_session, NULL,
-                                               target->url,
-                                               NULL, NULL, FALSE, FALSE,
-                                               ctx, scratch_pool));
-
-  SVN_ERR(calculate_left_hand_side(&source.url1, &source.rev1,
+  SVN_ERR(calculate_left_hand_side(&source.loc1.url, &source.loc1.rev,
                                    &merged_to_source_mergeinfo_catalog,
                                    &unmerged_to_source_mergeinfo_catalog,
-                                   target_abspath,
-                                   target_repos_rel_path,
+                                   target,
                                    subtrees_with_mergeinfo,
-                                   source.rev1,
-                                   source_repos_rel_path,
-                                   source_repos_root.url,
-                                   source.rev2,
+                                   source_loc,
                                    source_ra_session,
                                    target_ra_session,
                                    ctx,
@@ -10511,12 +10490,8 @@ find_reintegrate_merge(svn_ra_session_t 
 
   /* Did calculate_left_hand_side() decide that there was no merge to
      be performed here?  */
-  if (! source.url1)
+  if (! source.loc1.url)
     {
-      if (target_ra_session_p)
-        *target_ra_session_p = NULL;
-      if (source_ra_session_p)
-        *source_ra_session_p = NULL;
       if (source_p)
         *source_p = NULL;
       if (yc_ancestor_rev_p)
@@ -10524,31 +10499,38 @@ find_reintegrate_merge(svn_ra_session_t 
       return SVN_NO_ERROR;
     }
 
+  source.loc2 = *source_loc;
+
   /* If the target was moved after the source was branched from it,
      it is possible that the left URL differs from the target's current
      URL.  If so, then adjust TARGET_RA_SESSION to point to the old URL. */
-  if (strcmp(source.url1, target->url))
-    SVN_ERR(svn_ra_reparent(target_ra_session, source.url1, scratch_pool));
+  if (strcmp(source.loc1.url, target->loc.url))
+    SVN_ERR(svn_ra_reparent(target_ra_session, source.loc1.url, scratch_pool));
 
   SVN_ERR(svn_client__get_youngest_common_ancestor(&yc_ancestor_relpath, NULL,
                                                    &yc_ancestor_rev,
-                                                   source.url2, source.rev2,
-                                                   source.url1, source.rev1,
+                                                   source.loc2.url,
+                                                   source.loc2.rev,
+                                                   source.loc1.url,
+                                                   source.loc1.rev,
                                                    ctx, scratch_pool));
 
   if (!(yc_ancestor_relpath && SVN_IS_VALID_REVNUM(yc_ancestor_rev)))
     return svn_error_createf(SVN_ERR_CLIENT_NOT_READY_TO_MERGE, NULL,
                              _("'%s@%ld' must be ancestrally related to "
                                "'%s@%ld'"),
-                             source.url1, source.rev1,
-                             source.url2, source.rev2);
+                             source.loc1.url, source.loc1.rev,
+                             source.loc2.url, source.loc2.rev);
 
-  if (source.rev1 > yc_ancestor_rev)
+  if (source.loc1.rev > yc_ancestor_rev)
     {
       /* Have we actually merged anything to the source from the
          target?  If so, make sure we've merged a contiguous
          prefix. */
       svn_mergeinfo_t final_unmerged_catalog = apr_hash_make(scratch_pool);
+      const char *source_repos_rel_path
+        = svn_uri_skip_ancestor(source_loc->repo->url, source_loc->url,
+                                scratch_pool);
 
       SVN_ERR(find_unsynced_ranges(source_repos_rel_path,
                                    yc_ancestor_relpath,
@@ -10573,18 +10555,14 @@ find_reintegrate_merge(svn_ra_session_t 
                                      "previously merged from %s to the "
                                      "reintegrate source, but this is "
                                      "not the case:\n%s"),
-                                   yc_ancestor_rev + 1, source.rev2,
-                                   target->url,
+                                   yc_ancestor_rev + 1, source.loc2.rev,
+                                   target->loc.url,
                                    source_mergeinfo_cat_string->data);
         }
     }
 
   /* Left side: trunk@youngest-trunk-rev-merged-to-branch-at-specified-peg-rev
    * Right side: branch@specified-peg-revision */
-  if (target_ra_session_p)
-    *target_ra_session_p = target_ra_session;
-  if (source_ra_session_p)
-    *source_ra_session_p = source_ra_session;
   if (source_p)
     *source_p = apr_pmemdup(result_pool, &source, sizeof(source));
   if (yc_ancestor_rev_p)
@@ -10592,6 +10570,73 @@ find_reintegrate_merge(svn_ra_session_t 
   return SVN_NO_ERROR;
 }
 
+/* Resolve the source and target locations and open RA sessions to them, and
+ * perform some checks appropriate for a reintegrate merge.
+ *
+ * Set *SOURCE_RA_SESSION_P and *SOURCE_LOC_P to a new session and the
+ * repository location of SOURCE_PATH_OR_URL at SOURCE_PEG_REVISION.  Set
+ * *TARGET_RA_SESSION_P and *TARGET_P to a new session and the repository
+ * location of the WC at TARGET_ABSPATH.
+ *
+ * Throw a SVN_ERR_CLIENT_UNRELATED_RESOURCES error if the target WC node is
+ * a locally added node or if the source and target are not in the same
+ * repository.  Throw a SVN_ERR_CLIENT_NOT_READY_TO_MERGE error if the
+ * target WC is not at a single revision without switched subtrees and
+ * without local mods.
+ *
+ * Allocate all the outputs in RESULT_POOL.
+ */
+static svn_error_t *
+open_reintegrate_source_and_target(svn_ra_session_t **source_ra_session_p,
+                                   repo_location_t **source_loc_p,
+                                   svn_ra_session_t **target_ra_session_p,
+                                   merge_target_t **target_p,
+                                   const char *source_path_or_url,
+                                   const svn_opt_revision_t *source_peg_revision,
+                                   const char *target_abspath,
+                                   svn_client_ctx_t *ctx,
+                                   apr_pool_t *result_pool,
+                                   apr_pool_t *scratch_pool)
+{
+  repo_location_t *source_loc;
+  merge_target_t *target;
+
+  /* Open the target WC.  A reintegrate merge requires the merge target to
+   * reflect a subtree of the repository as found at a single revision. */
+  SVN_ERR(open_target_wc(&target, target_abspath,
+                         FALSE, FALSE, FALSE,
+                         ctx, scratch_pool, scratch_pool));
+  SVN_ERR(svn_client__open_ra_session_internal(target_ra_session_p, NULL,
+                                               target->loc.url,
+                                               NULL, NULL, FALSE, FALSE,
+                                               ctx, scratch_pool));
+  if (! target->loc.url)
+    return svn_error_createf(SVN_ERR_CLIENT_UNRELATED_RESOURCES, NULL,
+                             _("Can't reintegrate into '%s' because it is "
+                               "locally added and therefore not related to "
+                               "the merge source"),
+                             svn_dirent_local_style(target->abspath,
+                                                    scratch_pool));
+
+  SVN_ERR(open_source_session(&source_loc, source_ra_session_p,
+                              source_path_or_url, source_peg_revision,
+                              ctx, result_pool, scratch_pool));
+
+  /* source_loc->repo and target->loc.repo are required to be the same,
+     as mergeinfo doesn't come into play for cross-repository merging. */
+  SVN_ERR(check_same_repos(source_loc->repo,
+                           svn_dirent_local_style(source_path_or_url,
+                                                  scratch_pool),
+                           target->loc.repo,
+                           svn_dirent_local_style(target->abspath,
+                                                  scratch_pool),
+                           TRUE /* strict_urls */, scratch_pool));
+
+  *source_loc_p = source_loc;
+  *target_p = target;
+  return SVN_NO_ERROR;
+}
+
 svn_error_t *
 svn_client_find_reintegrate_merge(const char **url1_p,
                                   svn_revnum_t *rev1_p,
@@ -10605,20 +10650,30 @@ svn_client_find_reintegrate_merge(const 
                                   apr_pool_t *scratch_pool)
 {
   const char *target_abspath;
+  svn_ra_session_t *source_ra_session;
+  repo_location_t *source_loc;
+  svn_ra_session_t *target_ra_session;
+  merge_target_t *target;
   merge_source_t *source;
 
   SVN_ERR(svn_dirent_get_absolute(&target_abspath, target_wcpath,
                                   scratch_pool));
-  SVN_ERR(find_reintegrate_merge(NULL, NULL, &source, NULL,
-                                 source_path_or_url, source_peg_revision,
-                                 target_abspath,
+
+  SVN_ERR(open_reintegrate_source_and_target(
+            &source_ra_session, &source_loc, &target_ra_session, &target,
+            source_path_or_url, source_peg_revision, target_abspath,
+            ctx, scratch_pool, scratch_pool));
+
+  SVN_ERR(find_reintegrate_merge(&source, NULL,
+                                 source_ra_session, source_loc,
+                                 target_ra_session, target,
                                  ctx, result_pool, scratch_pool));
   if (source)
     {
-      *url1_p = source->url1;
-      *rev1_p = source->rev1;
-      *url2_p = source->url2;
-      *rev2_p = source->rev2;
+      *url1_p = source->loc1.url;
+      *rev1_p = source->loc1.rev;
+      *url2_p = source->loc2.url;
+      *rev2_p = source->loc2.rev;
     }
   else
     {
@@ -10642,18 +10697,20 @@ merge_reintegrate_locked(const char *sou
 {
   svn_ra_session_t *target_ra_session, *source_ra_session;
   merge_target_t *target;
+  repo_location_t *source_loc;
   merge_source_t *source;
   svn_revnum_t yc_ancestor_rev;
   svn_boolean_t use_sleep;
   svn_error_t *err;
 
-  SVN_ERR(target_node_location(&target, target_abspath,
-                               ctx, scratch_pool, scratch_pool));
-
-  SVN_ERR(find_reintegrate_merge(&target_ra_session, &source_ra_session,
-                                 &source, &yc_ancestor_rev,
-                                 source_path_or_url, source_peg_revision,
-                                 target_abspath,
+  SVN_ERR(open_reintegrate_source_and_target(
+            &source_ra_session, &source_loc, &target_ra_session, &target,
+            source_path_or_url, source_peg_revision, target_abspath,
+            ctx, scratch_pool, scratch_pool));
+
+  SVN_ERR(find_reintegrate_merge(&source, &yc_ancestor_rev,
+                                 source_ra_session, source_loc,
+                                 target_ra_session, target,
                                  ctx, scratch_pool, scratch_pool));
 
   if (! source)
@@ -10733,10 +10790,8 @@ merge_peg_locked(const char *source_path
                  apr_pool_t *scratch_pool)
 {
   merge_target_t *target;
-  const char *source_url;
-  svn_revnum_t source_peg_revnum;
+  repo_location_t *source_loc;
   apr_array_header_t *merge_sources;
-  url_uuid_t source_repos_root;
   svn_ra_session_t *ra_session;
   apr_pool_t *sesspool;
   svn_boolean_t use_sleep = FALSE;
@@ -10745,30 +10800,24 @@ merge_peg_locked(const char *source_path
 
   SVN_ERR_ASSERT(svn_dirent_is_absolute(target_abspath));
 
-  SVN_ERR(target_node_location(&target, target_abspath,
-                               ctx, scratch_pool, scratch_pool));
-  SVN_ERR(ensure_wc_is_suitable_merge_target(target_abspath, ctx,
-                                             allow_mixed_rev, TRUE, TRUE,
-                                             scratch_pool));
+  SVN_ERR(open_target_wc(&target, target_abspath,
+                         allow_mixed_rev, TRUE, TRUE,
+                         ctx, scratch_pool, scratch_pool));
 
   /* Open an RA session to our source URL, and determine its root URL. */
   sesspool = svn_pool_create(scratch_pool);
-  SVN_ERR(svn_client__ra_session_from_path(
-            &ra_session, &source_peg_revnum, &source_url,
-            source_path_or_url, NULL, source_peg_revision, source_peg_revision,
-            ctx, sesspool));
-  SVN_ERR(svn_ra_get_repos_root2(ra_session, &source_repos_root.url,
-                                 scratch_pool));
-  SVN_ERR(svn_ra_get_uuid2(ra_session, &source_repos_root.uuid, scratch_pool));
+  SVN_ERR(open_source_session(&source_loc, &ra_session,
+                              source_path_or_url, source_peg_revision,
+                              ctx, sesspool, scratch_pool));
 
   /* Normalize our merge sources. */
   SVN_ERR(normalize_merge_sources(&merge_sources, source_path_or_url,
-                                  source_url, source_peg_revnum,
+                                  source_loc->url, source_loc->rev,
                                   ranges_to_merge, ra_session, ctx,
                                   scratch_pool, scratch_pool));
 
   /* Check for same_repos. */
-  same_repos = is_same_repos(&target->repos_root, &source_repos_root,
+  same_repos = is_same_repos(target->loc.repo, source_loc->repo,
                              TRUE /* strict_urls */);
 
   /* We're done with our little RA session. */
@@ -10831,3 +10880,421 @@ svn_client_merge_peg4(const char *source
 
   return SVN_NO_ERROR;
 }
+
+#ifdef SVN_WITH_SYMMETRIC_MERGE
+
+/* Details of a symmetric merge. */
+struct svn_client__symmetric_merge_t
+{
+  repo_location_t *yca, *base, *mid, *right;
+};
+
+/* */
+typedef struct source_and_target_t
+{
+  repo_location_t *source;
+  svn_ra_session_t *source_ra_session;
+  merge_target_t *target;
+  svn_ra_session_t *target_ra_session;
+} source_and_target_t;
+
+/* "Open" the source and target branches of a merge.  That means:
+ *   - find out their exact repository locations (resolve WC paths and
+ *     non-numeric revision numbers),
+ *   - check the branches are suitably related,
+ *   - establish RA session(s) to the repo,
+ *   - check the WC for suitability (throw an error if unsuitable)
+ *
+ * Record this information and return it in a new "merge context" object.
+ */
+static svn_error_t *
+open_source_and_target(source_and_target_t **source_and_target,
+                       const char *source_path_or_url,
+                       const svn_opt_revision_t *source_peg_revision,
+                       const char *target_abspath,
+                       svn_boolean_t allow_mixed_rev,
+                       svn_boolean_t allow_local_mods,
+                       svn_boolean_t allow_switched_subtrees,
+                       svn_client_ctx_t *ctx,
+                       apr_pool_t *session_pool,
+                       apr_pool_t *result_pool,
+                       apr_pool_t *scratch_pool)
+{
+  source_and_target_t *s_t = apr_palloc(result_pool, sizeof(*s_t));
+
+  /* Target */
+  SVN_ERR(open_target_wc(&s_t->target, target_abspath,
+                         allow_mixed_rev, allow_local_mods, allow_switched_subtrees,
+                         ctx, result_pool, scratch_pool));
+  SVN_ERR(svn_client_open_ra_session(&s_t->target_ra_session,
+                                     s_t->target->loc.url,
+                                     ctx, session_pool));
+
+  /* Source */
+  SVN_ERR(open_source_session(&s_t->source, &s_t->source_ra_session,
+                              source_path_or_url, source_peg_revision,
+                              ctx, result_pool, scratch_pool));
+
+  *source_and_target = s_t;
+  return SVN_NO_ERROR;
+}
+
+/* "Close" any resources that were acquired in the S_T structure. */
+static svn_error_t *
+close_source_and_target(source_and_target_t *s_t,
+                        apr_pool_t *scratch_pool)
+{
+  /* close s_t->source_/target_ra_session */
+  return SVN_NO_ERROR;
+}
+
+/* Find a merge base location on the target branch, like in a sync
+ * merge.
+ *
+ *          (Source-left) (Source-right = S_T->source)
+ *                BASE        RIGHT
+ *          o-------o-----------o---
+ *         /         \           \
+ *   -----o     prev. \           \  this
+ *     YCA \    merge  \           \ merge
+ *          o-----------o-----------o
+ *                                TARGET
+ *
+ */
+static svn_error_t *
+find_base_on_source(repo_location_t **base_p,
+                    source_and_target_t *s_t,
+                    svn_client_ctx_t *ctx,
+                    apr_pool_t *result_pool,
+                    apr_pool_t *scratch_pool)
+{
+  svn_mergeinfo_t target_mergeinfo;
+  svn_client__merge_path_t *merge_target;
+  svn_boolean_t inherited;
+  merge_source_t source;
+  svn_merge_range_t *r;
+  repo_location_t *base;
+
+  merge_target = svn_client__merge_path_create(s_t->target->abspath,
+                                               scratch_pool);
+
+  /* Fetch target mergeinfo (all the way back to revision 1). */
+  SVN_ERR(get_full_mergeinfo(&target_mergeinfo,
+                             &merge_target->implicit_mergeinfo,
+                             &inherited, svn_mergeinfo_inherited,
+                             s_t->target_ra_session, s_t->target->abspath,
+                             s_t->source->rev, 1,
+                             ctx, scratch_pool, scratch_pool));
+
+  /* In order to find the first unmerged change in the source, set
+   * MERGE_TARGET->remaining_ranges to the ranges left to merge,
+   * and look at the start revision of the first such range. */
+  source.loc1.url = s_t->source->url;  /* ### WRONG: need historical URL/REV */
+  source.loc1.rev = 1;
+  source.loc2 = *s_t->source;
+  SVN_ERR(calculate_remaining_ranges(NULL, merge_target,
+                                     &source,
+                                     target_mergeinfo,
+                                     NULL /*merge_b->implicit_src_gap*/,
+                                     FALSE /*child_inherits_implicit*/,
+                                     s_t->source_ra_session,
+                                     ctx, scratch_pool, scratch_pool));
+
+  r = APR_ARRAY_IDX(merge_target->remaining_ranges, 0, svn_merge_range_t *);
+  base = apr_palloc(result_pool, sizeof(*base));
+  base->url = s_t->source->url;  /* ### WRONG: need historical URL */
+  base->rev = r->start;
+
+  *base_p = base;
+  return SVN_NO_ERROR;
+}
+
+/* Find a merge base location on the target branch, like in a reintegrate
+ * merge.
+ * 
+ *                     MID    RIGHT
+ *          o-----------o-------o---
+ *         /    prev.  /         \
+ *   -----o     merge /           \  this
+ *     YCA \         /             \ merge
+ *          o-------o---------------o
+ *                BASE            TARGET
+ *
+ * Set *BASE_P to the latest location on the history of S_T->target at
+ * which all revisions up to *BASE_P are recorded as merged into RIGHT
+ * (which is S_T->source).
+ * 
+ * ### TODO: Set *MID_P to the first location on the history of
+ * S_T->source at which all revisions up to BASE_P are recorded as merged.
+ */
+static svn_error_t *
+find_base_on_target(repo_location_t **base_p,
+                    repo_location_t **mid_p,
+                    source_and_target_t *s_t,
+                    svn_client_ctx_t *ctx,
+                    apr_pool_t *result_pool,
+                    apr_pool_t *scratch_pool)
+{
+  repo_location_t *base = apr_palloc(result_pool, sizeof(*base));
+  svn_mergeinfo_t unmerged_to_source_mergeinfo_catalog;
+  svn_mergeinfo_t merged_to_source_mergeinfo_catalog;
+  apr_hash_t *subtrees_with_mergeinfo;
+
+  /* Find all the subtrees in TARGET_WCPATH that have explicit mergeinfo. */
+  SVN_ERR(get_wc_explicit_mergeinfo_catalog(&subtrees_with_mergeinfo,
+                                            s_t->target->abspath,
+                                            svn_depth_infinity,
+                                            ctx, scratch_pool, scratch_pool));
+
+  SVN_ERR(calculate_left_hand_side(&base->url, &base->rev,
+                                   &merged_to_source_mergeinfo_catalog,

[... 251 lines stripped ...]