From 9e2d884d0fcf0631164c33d458a251bee6053bb1 Mon Sep 17 00:00:00 2001 From: Ævar Arnfjörð Bjarmason Date: Tue, 28 Mar 2023 16:04:27 +0200 Subject: config API: add "string" version of *_value_multi(), fix segfaults MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix numerous and mostly long-standing segfaults in consumers of the *_config_*value_multi() API. As discussed in the preceding commit an empty key in the config syntax yields a "NULL" string, which these users would give to strcmp() (or similar), resulting in segfaults. As this change shows, most users users of the *_config_*value_multi() API didn't really want such an an unsafe and low-level API, let's give them something with the safety of git_config_get_string() instead. This fix is similar to what the *_string() functions and others acquired in[1] and [2]. Namely introducing and using a safer "*_get_string_multi()" variant of the low-level "_*value_multi()" function. This fixes segfaults in code introduced in: - d811c8e17c6 (versionsort: support reorder prerelease suffixes, 2015-02-26) - c026557a373 (versioncmp: generalize version sort suffix reordering, 2016-12-08) - a086f921a72 (submodule: decouple url and submodule interest, 2017-03-17) - a6be5e6764a (log: add log.excludeDecoration config option, 2020-04-16) - 92156291ca8 (log: add default decoration filter, 2022-08-05) - 50a044f1e40 (gc: replace config subprocesses with API calls, 2022-09-27) There are now two users ofthe low-level API: - One in "builtin/for-each-repo.c", which we'll convert in a subsequent commit. - The "t/helper/test-config.c" code added in [3]. As seen in the preceding commit we need to give the "t/helper/test-config.c" caller these "NULL" entries. We could also alter the underlying git_configset_get_value_multi() function to be "string safe", but doing so would leave no room for other variants of "*_get_value_multi()" that coerce to other types. Such coercion can't be built on the string version, since as we've established "NULL" is a true value in the boolean context, but if we coerced it to "" for use in a list of strings it'll be subsequently coerced to "false" as a boolean. The callback pattern being used here will make it easy to introduce e.g. a "multi" variant which coerces its values to "bool", "int", "path" etc. 1. 40ea4ed9032 (Add config_error_nonbool() helper function, 2008-02-11) 2. 6c47d0e8f39 (config.c: guard config parser from value=NULL, 2008-02-11). 3. 4c715ebb96a (test-config: add tests for the config_set API, 2014-07-28) Signed-off-by: Ævar Arnfjörð Bjarmason Signed-off-by: Junio C Hamano --- versioncmp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'versioncmp.c') diff --git a/versioncmp.c b/versioncmp.c index 60c3a51712..7498da96e0 100644 --- a/versioncmp.c +++ b/versioncmp.c @@ -164,8 +164,8 @@ int versioncmp(const char *s1, const char *s2) const char *const oldk = "versionsort.prereleasesuffix"; const struct string_list *newl; const struct string_list *oldl; - int new = git_config_get_value_multi(newk, &newl); - int old = git_config_get_value_multi(oldk, &oldl); + int new = git_config_get_string_multi(newk, &newl); + int old = git_config_get_string_multi(oldk, &oldl); if (!new && !old) warning("ignoring %s because %s is set", oldk, newk); -- cgit v1.2.3