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2017-01-12versioncmp: generalize version sort suffix reorderingLibravatar SZEDER Gábor1-1/+8
The 'versionsort.prereleaseSuffix' configuration variable, as its name suggests, is supposed to only deal with tagnames with prerelease suffixes, and allows sorting those prerelease tags in a user-defined order before the suffixless main release tag, instead of sorting them simply lexicographically. However, the previous changes in this series resulted in an interesting and useful property of version sort: - The empty string as a configured suffix matches all tagnames, including tagnames without any suffix, but - tagnames containing a "real" configured suffix are still ordered according to that real suffix, because any longer suffix takes precedence over the empty string. Exploiting this property we can easily generalize suffix reordering and specify the order of tags with given suffixes not only before but even after a main release tag by using the empty suffix to denote the position of the main release tag, without any algorithm changes: $ git -c versionsort.prereleaseSuffix=-alpha \ -c versionsort.prereleaseSuffix=-beta \ -c versionsort.prereleaseSuffix="" \ -c versionsort.prereleaseSuffix=-gamma \ -c versionsort.prereleaseSuffix=-delta \ tag -l --sort=version:refname 'v3.0*' v3.0-alpha1 v3.0-beta1 v3.0 v3.0-gamma1 v3.0-delta1 Since 'versionsort.prereleaseSuffix' is not a fitting name for a configuration variable to control this more general suffix reordering, introduce the new variable 'versionsort.suffix'. Still keep the old configuration variable name as a deprecated alias, though, to avoid suddenly breaking setups already using it. Ignore the old variable if both old and new configuration variables are set, but emit a warning so users will be aware of it and can fix their configuration. Extend the documentation to describe and add a test to check this more general behavior. Note: since the empty suffix matches all tagnames, tagnames with suffixes not included in the configuration are listed together with the suffixless main release tag, ordered lexicographically right after that, i.e. before tags with suffixes listed in the configuration following the empty suffix. Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-12versioncmp: factor out helper for suffix matchingLibravatar SZEDER Gábor1-25/+39
As the number of identical steps to be done for both tagnames grows, extract them into a helper function, with the additional benefit that the conditionals near the end of swap_prereleases() will use more meaningful variable names. Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-08versioncmp: use earliest-longest contained suffix to determine sorting orderLibravatar SZEDER Gábor1-8/+25
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 <szeder.dev@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-08versioncmp: cope with common part overlapping with prerelease suffixLibravatar SZEDER Gábor1-7/+21
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>
2016-12-08versioncmp: pass full tagnames to swap_prereleases()Libravatar SZEDER Gábor1-16/+13
The swap_prereleases() helper function is responsible for finding configured prerelease suffixes in a pair of tagnames to be compared, but this function currently gets to see only the parts of those two tagnames starting at the first different character. To fix some issues related to the common part of two tagnames overlapping with leading part of a prerelease suffix, this helper function must see both full tagnames. In preparation for the fix in the following patch, refactor swap_prereleases() and its caller to pass two full tagnames and an additional offset indicating the position of the first different character. While updating the comment describing that function, remove the sentence about not dealing with both tagnames having the same suffix. Currently it doesn't add much value (we know that there is a different character, so it's obvious that it can't possibly be the same suffix in both), and at the end of this patch series it won't even be true anymore. Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-27versionsort: support reorder prerelease suffixesLibravatar Nguyễn Thái Ngọc Duy1-0/+50
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-27tag: support --sort=<spec>Libravatar Nguyễn Thái Ngọc Duy1-0/+93
--sort=version:refname (or --sort=v:refname for short) sorts tags as if they are versions. --sort=-refname reverses the order (with or without ":version"). versioncmp() is copied from string/strverscmp.c in glibc commit ee9247c38a8def24a59eb5cfb7196a98bef8cfdc, reformatted to Git coding style. The implementation is under LGPL-2.1 and according to [1] I can relicense it to GPLv2. [1] http://www.gnu.org/licenses/gpl-faq.html#AllCompatibility Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>