From 51acfa9db588ddd8c3aff2acbc1a85ae7ac239f6 Mon Sep 17 00:00:00 2001 From: SZEDER Gábor Date: Thu, 8 Dec 2016 15:24:00 +0100 Subject: versioncmp: use earliest-longest contained suffix to determine sorting order MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When comparing tagnames, it is possible that a tagname contains more than one of the configured prerelease suffixes around the first different character. After fixing a bug in the previous commit such a tagname is sorted according to the contained suffix which comes first in the configuration. This is, however, not quite the right thing to do in the following corner cases: 1. $ git -c versionsort.suffix=-bar -c versionsort.suffix=-foo-baz -c versionsort.suffix=-foo-bar tag -l --sort=version:refname 'v1*' v1.0-foo-bar v1.0-foo-baz The suffix of the tagname 'v1.0-foo-bar' is clearly '-foo-bar', so it should be listed last. However, as it also contains '-bar' around the first different character, it is listed first instead, because that '-bar' suffix comes first the configuration. 2. One of the configured suffixes starts with the other: $ git -c versionsort.prereleasesuffix=-pre \ -c versionsort.prereleasesuffix=-prerelease \ tag -l --sort=version:refname 'v2*' v2.0-prerelease1 v2.0-pre1 v2.0-pre2 Here the tagname 'v2.0-prerelease1' should be the last. When comparing 'v2.0-pre1' and 'v2.0-prerelease1' the first different characters are '1' and 'r', respectively. Since this first different character must be part of the configured suffix, the '-pre' suffix is not recognized in the first tagname. OTOH, the '-prerelease' suffix is properly recognized in 'v2.0-prerelease1', thus it is listed first. Improve version sort in these corner cases, and - look for a configured prerelease suffix containing the first different character or ending right before it, so the '-pre' suffixes are recognized in case (2). This also means that when comparing tagnames 'v2.0-pre1' and 'v2.0-pre2', swap_prereleases() would find the '-pre' suffix in both, but then it will return "undecided" and the caller will do the right thing by sorting based in '1' and '2'. - If the tagname contains more than one suffix, then give precedence to the contained suffix that starts at the earliest offset in the tagname to address (1). - If there are more than one suffixes starting at that earliest position, then give precedence to the longest of those suffixes, thus ensuring that in (2) the tagname 'v2.0-prerelease1' won't be sorted based on the '-pre' suffix. Add tests for these corner cases and adjust the documentation accordingly. Signed-off-by: SZEDER Gábor Signed-off-by: Junio C Hamano --- versioncmp.c | 33 +++++++++++++++++++++++++-------- 1 file changed, 25 insertions(+), 8 deletions(-) (limited to 'versioncmp.c') diff --git a/versioncmp.c b/versioncmp.c index f86ac562e2..ae0a9199bd 100644 --- a/versioncmp.c +++ b/versioncmp.c @@ -27,14 +27,18 @@ 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 containing - * that offset, then that string will be forced to be on top. + * that offset or a suffix ends right before that offset, then that + * string will be forced to be on top. * * 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. + * suffix which starts at the earliest offset in that string. + * If more than one different contained suffixes start at that earliest + * offset, then that string is sorted according to the longest of those + * suffixes. * * Return non-zero if *diff contains the return value for versioncmp() */ @@ -44,27 +48,40 @@ static int swap_prereleases(const char *s1, int *diff) { int i, i1 = -1, i2 = -1; + int start_at1 = off, start_at2 = off, match_len1 = -1, match_len2 = -1; for (i = 0; i < prereleases->nr; i++) { const char *suffix = prereleases->items[i].string; - int j, start, suffix_len = strlen(suffix); + int j, start, end, suffix_len = strlen(suffix); if (suffix_len < off) - start = off - suffix_len + 1; + start = off - suffix_len; else start = 0; - for (j = start; j <= off; j++) - if (i1 == -1 && starts_with(s1 + j, suffix)) { + end = match_len1 < suffix_len ? start_at1 : start_at1-1; + for (j = start; j <= end; j++) + if (starts_with(s1 + j, suffix)) { i1 = i; + start_at1 = j; + match_len1 = suffix_len; break; } - for (j = start; j <= off; j++) - if (i2 == -1 && starts_with(s2 + j, suffix)) { + end = match_len2 < suffix_len ? start_at2 : start_at2-1; + for (j = start; j <= end; j++) + if (starts_with(s2 + j, suffix)) { i2 = i; + start_at2 = j; + match_len2 = suffix_len; break; } } if (i1 == -1 && i2 == -1) return 0; + if (i1 == i2) + /* Found the same suffix in both, e.g. "-rc" in "v1.0-rcX" + * and "v1.0-rcY": the caller should decide based on "X" + * and "Y". */ + return 0; + if (i1 >= 0 && i2 >= 0) *diff = i1 - i2; else if (i1 >= 0) -- cgit v1.3