[Bug 40453] lexicographic compare in RewriteCond isn't lexicographic

[bu...@apache.org]

https://bz.apache.org/bugzilla/show_bug.cgi?id=40453

--- Comment #4 from Rich Bowen <rb...@apache.org> ---
This is a code bug, not just a documentation issue. The
compare_lexicography() function in mod_rewrite.c (around L4102
in trunk) compares string lengths first: when strings differ in
length, the longer string is always "greater" regardless of
content. "AAA" > "B" is objectively wrong.

The case-insensitive path ([NC] flag) correctly uses strcasecmp()
and does not have this problem.

The fix is a one-liner — replace the length-first logic with
strcmp():

--- a/modules/mappers/mod_rewrite.c
+++ b/modules/mappers/mod_rewrite.c
 static APR_INLINE int compare_lexicography(char *a, char *b)
 {
-    apr_size_t i, lena, lenb;
-
-    lena = strlen(a);
-    lenb = strlen(b);
-
-    if (lena == lenb) {
-        for (i = 0; i < lena; ++i) {
-            if (a[i] != b[i]) {
-                return ((unsigned char)a[i] > (unsigned char)b[i]) ? 1 : -1;
-            }
-        }
-
-        return 0;
-    }
-
-    return ((lena > lenb) ? 1 : -1);
+    return strcmp(a, b);
 }

I don't think "historical behavior" is a reason to preserve this.
Nobody is relying on "AAA" being greater than "B" — and if they
are, their config is already broken in ways they don't realize.

-- 
You are receiving this mail because:
You are the assignee for the bug.
---------------------------------------------------------------------
To unsubscribe, e-mail: bugs-unsubscribe@httpd.apache.org
For additional commands, e-mail: bugs-help@httpd.apache.org