[PATCH] mingw: abort on invalid strftime formats
- From
Johannes Schindelin <johannes.schindelin@gmx.de>
- Date
- Mar 19, 2018, 16:49 UTC
- Message-ID
- <66189602d022dd1911b5f5d98594506b80bb81ff.1521478106.git.johannes.schindelin@gmx.de>
On Windows, strftime() does not silently ignore invalid formats, but warns about them and then returns 0 and sets errno to EINVAL.
Unfortunately, Git does not expect such a behavior, as it disagrees with strftime()'s semantics on Linux. As a consequence, Git misinterprets the return value 0 as "I need more space" and grows the buffer. As the larger buffer does not fix the format, the buffer grows and grows and grows until we are out of memory and abort.
Ideally, we would switch off the parameter validation just for strftime(), but we cannot even override the invalid parameter handler via _set_thread_local_invalid_parameter_handler() using MINGW because that function is not declared. Even _set_invalid_parameter_handler(), which *is* declared, does not help, as it simply does... nothing.
So let's just bite the bullet and override strftime() for MINGW and abort on an invalid format string. While this does not provide the best user experience, it is the best we can do.
See https://msdn.microsoft.com/en-us/library/fe06s4ak.aspx for more details.
This fixes https://github.com/git-for-windows/git/issues/863
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> ---
This is a really old patch (from 2016) that I had not managed to contribute to git.git yet...
compat/mingw.c | 11 +++++++++++ compat/mingw.h | 3 +++ 2 files changed, 14 insertions(+)
diff --git a/compat/mingw.c b/compat/mingw.c index 2d44d21aca8..a67872babf3 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -761,6 +761,17 @@ int mingw_utime (const char *file_name, const struct utimbuf *times) return rc; } +#undef strftime +size_t mingw_strftime(char *s, size_t max, + const char *format, const struct tm *tm) +{ + size_t ret = strftime(s, max, format, tm); + + if (!ret && errno == EINVAL) + die("invalid strftime format: '%s'", format); + return ret; +} + unsigned int sleep (unsigned int seconds) { Sleep(seconds*1000); diff --git a/compat/mingw.h b/compat/mingw.h index e03aecfe2e6..571019d0bdd 100644 --- a/compat/mingw.h +++ b/compat/mingw.h @@ -361,6 +361,9 @@ int mingw_fstat(int fd, struct stat *buf); int mingw_utime(const char *file_name, const struct utimbuf *times); #define utime mingw_utime +size_t mingw_strftime(char *s, size_t max, + const char *format, const struct tm *tm); +#define strftime mingw_strftime pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env, const char *dir, base-commit: 0afbf6caa5b16dcfa3074982e5b48e27d452dbbb
-- 2.16.1.windows.4 Published-As: https://github.com/dscho/git/releases/tag/mingw-strftime-v1 Fetch-It-Via: git fetch https://github.com/dscho/git mingw-strftime-v1