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authorSZEDER Gábor <szeder.dev@gmail.com>2016-12-08 15:23:59 +0100
committerJunio C Hamano <gitster@pobox.com>2016-12-08 11:11:57 -0800
commitb8231660fa95f6e9e07b9e2483e254c2de045275 (patch)
treef299177cb1b1b1ad74e4e9c3736a6653be7f8c62 /versioncmp.c
parent109064a0313c8a7c337f37936077ef3c9171d7ce (diff)
downloadgit-b8231660fa95f6e9e07b9e2483e254c2de045275.tar.gz
versioncmp: cope with common part overlapping with prerelease suffix
Version sort with prerelease reordering sometimes puts tagnames in the wrong order, when the common part of two compared tagnames overlaps with the leading character(s) of one or more configured prerelease suffixes. Note the position of "v2.1.0-beta-1": $ git -c versionsort.prereleaseSuffix=-beta \ tag -l --sort=version:refname v2.1.* v2.1.0-beta-2 v2.1.0-beta-3 v2.1.0 v2.1.0-RC1 v2.1.0-RC2 v2.1.0-beta-1 v2.1.1 v2.1.2 The reason is that when comparing a pair of tagnames, first versioncmp() looks for the first different character in a pair of tagnames, and then the swap_prereleases() helper function looks for a configured prerelease suffix _starting at_ that character. Thus, when in the above example the sorting algorithm happens to compare the tagnames "v2.1.0-beta-1" and "v2.1.0-RC2", swap_prereleases() tries to match the suffix "-beta" against "beta-1" to no avail, and the two tagnames erroneously end up being ordered lexicographically. To fix this issue change swap_prereleases() to look for configured prerelease suffixes _containing_ the position of that first different character. Care must be taken, when a configured suffix is longer than the tagnames' common part up to the first different character, to avoid reading memory before the beginning of the tagnames. Add a test that uses an exceptionally long prerelease suffix to check for this, in the hope that in case of a regression the illegal memory access causes a segfault in 'git tag' on one of the commonly used platforms (the test happens to pass successfully on my Linux system with the safety check removed), or at least makes valgrind complain. Under some circumstances it's possible that more than one prerelease suffixes can be found in the same tagname around that first different character. With this simple bugfix patch such a tagname is sorted according to the contained suffix that comes first in the configuration for now. This is less than ideal in some cases, and the following patch will take care of those. Reported-by: Leho Kraav <leho@conversionready.com> Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'versioncmp.c')
-rw-r--r--versioncmp.c28
1 files changed, 21 insertions, 7 deletions
diff --git a/versioncmp.c b/versioncmp.c
index a55c23ad57..f86ac562e2 100644
--- 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;