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Posted to cvs@httpd.apache.org by fi...@apache.org on 2009/02/12 02:59:28 UTC
svn commit: r743595 - /httpd/httpd/trunk/modules/filters/mod_deflate.c
Author: fielding
Date: Thu Feb 12 01:59:27 2009
New Revision: 743595
URL: http://svn.apache.org/viewvc?rev=743595&view=rev
Log:
Reimplement deflate_check_etag() so that it isn't such a pig
and correctly works with weak etags. Related to PR 39727.
Note that there remains an error in ap_meets_conditions because
that function does not currently check for a transformed etag.
I am working on that.
Modified:
httpd/httpd/trunk/modules/filters/mod_deflate.c
Modified: httpd/httpd/trunk/modules/filters/mod_deflate.c
URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/modules/filters/mod_deflate.c?rev=743595&r1=743594&r2=743595&view=diff
==============================================================================
--- httpd/httpd/trunk/modules/filters/mod_deflate.c (original)
+++ httpd/httpd/trunk/modules/filters/mod_deflate.c Thu Feb 12 01:59:27 2009
@@ -381,26 +381,43 @@
ctx->libz_end_func(&ctx->stream);
return APR_SUCCESS;
}
-/* PR 39727: we're screwing up our clients if we leave a strong ETag
- * header while transforming content. Henrik Nordstrom suggests
- * appending ";gzip".
- *
- * Pending a more thorough review of our Etag handling, let's just
- * implement his suggestion. It fixes the bug, or at least turns it
- * from a showstopper to an inefficiency. And it breaks nothing that
- * wasn't already broken.
+
+/* ETag must be unique among the possible representations, so a change
+ * to content-encoding requires a corresponding change to the ETag.
+ * This routine appends -transform (e.g., -gzip) to the entity-tag
+ * value inside the double-quotes if an ETag has already been set
+ * and its value already contains double-quotes. PR 39727
*/
static void deflate_check_etag(request_rec *r, const char *transform)
{
const char *etag = apr_table_get(r->headers_out, "ETag");
- if ((etag && (strlen(etag) > 2))) {
- if (etag[0] == '"') {
- etag = apr_pstrndup(r->pool, etag, strlen(etag) - 1);
- apr_table_set(r->headers_out, "ETag",
- apr_pstrcat(r->pool, etag, "-", transform, "\"", NULL));
+ apr_size_t etaglen;
+
+ if ((etag && ((etaglen = strlen(etag)) > 2))) {
+ if (etag[etaglen - 1] == '"') {
+ apr_size_t transformlen = strlen(transform);
+ char *newtag = apr_palloc(r->pool, etaglen + transformlen + 2);
+ char *d = newtag;
+ char *e = d + etaglen - 1;
+ const char *s = etag;
+
+ for (; d < e; ++d, ++s) {
+ *d = *s; /* copy etag to newtag up to last quote */
+ }
+ *d++ = '-'; /* append dash to newtag */
+ s = transform;
+ e = d + transformlen;
+ for (; d < e; ++d, ++s) {
+ *d = *s; /* copy transform to newtag */
+ }
+ *d++ = '"'; /* append quote to newtag */
+ *d = '\0'; /* null terminate newtag */
+
+ apr_table_setn(r->headers_out, "ETag", newtag);
}
}
}
+
static apr_status_t deflate_out_filter(ap_filter_t *f,
apr_bucket_brigade *bb)
{