versioncmp: cope with common part overlapping with prerelease suffix

[thirdparty/git.git] / versioncmp.c

diff --git a/versioncmp.c b/versioncmp.c
index a55c23ad57041a6f01b206e940706afb29cf21af..f86ac562e294c59c829ff6da60eb0f99c712c0b4 100644 (file)
--- a/versioncmp.c
+++ b/versioncmp.c
@@ -26,12 +26,15 @@ static int initialized;
 
 /*
  * off is the offset of the first different character in the two strings
- * s1 and s2. If either s1 or s2 contains a prerelease suffix starting
- * at that offset, it will be forced to be on top.
+ * s1 and s2. If either s1 or s2 contains a prerelease suffix containing
+ * that offset, then that string will be forced to be on top.
  *
- * If both s1 and s2 contain a (different) suffix at that position,
+ * If both s1 and s2 contain a (different) suffix around that position,
  * their order is determined by the order of those two suffixes in the
  * configuration.
+ * If any of the strings contains more than one different suffixes around
+ * that position, then that string is sorted according to the contained
+ * suffix which comes first in the configuration.
  *
  * Return non-zero if *diff contains the return value for versioncmp()
  */
@@ -44,10 +47,21 @@ static int swap_prereleases(const char *s1,
 
        for (i = 0; i < prereleases->nr; i++) {
                const char *suffix = prereleases->items[i].string;
-               if (i1 == -1 && starts_with(s1 + off, suffix))
-                       i1 = i;
-               if (i2 == -1 && starts_with(s2 + off, suffix))
-                       i2 = i;
+               int j, start, suffix_len = strlen(suffix);
+               if (suffix_len < off)
+                       start = off - suffix_len + 1;
+               else
+                       start = 0;
+               for (j = start; j <= off; j++)
+                       if (i1 == -1 && starts_with(s1 + j, suffix)) {
+                               i1 = i;
+                               break;
+                       }
+               for (j = start; j <= off; j++)
+                       if (i2 == -1 && starts_with(s2 + j, suffix)) {
+                               i2 = i;
+                               break;
+                       }
        }
        if (i1 == -1 && i2 == -1)
                return 0;