mingw: use strftime() directly in UCRT builds

From: Johannes Schindelin <[email protected]>

The mingw_strftime() wrapper exists to work around msvcrt.dll's incomplete strftime() implementation by dynamically loading the version from ucrtbase.dll at runtime via LoadLibrary() + GetProcAddress(). When the binary is already linked against UCRT (i.e. when building in the UCRT64 environment), the linked-in strftime() is the ucrtbase.dll version, making the dynamic loading needless churn: It's calling the very same code.

Simply guard both the declaration and implementation so that the unnecessary work-around is skipped in UCRT builds.

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mingw: use strftime() directly in UCRT builds

Since the MSYS2 project deprecated the MINGW64 environment
[https://www.msys2.org/news/#2026-03-15-deprecating-the-mingw64-environment]
on which Git for Windows relies, we have to prepare quite swiftly for a future where we switch to the UCRT64 environment instead. This patch is the only fall-out of that that concerns the Git source code.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2079%2Fdscho%2Fmingw-use-strftime-directly-in-UCRT-builds-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2079/dscho/mingw-use-strftime-directly-in-UCRT-builds-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/2079

 compat/mingw.c | 4 ++++
 1 file changed, 4 insertions(+)

index c667a2dcda..338ec3535e 100644
@@ -1394,6 +1394,9 @@ revert_attrs:
 size_t mingw_strftime(char *s, size_t max,
 		      const char *format, const struct tm *tm)
 {
+#ifdef _UCRT
+	size_t ret = strftime(s, max, format, tm);
+#else
 	/* a pointer to the original strftime in case we can't find the UCRT version */
 	static size_t (*fallback)(char *, size_t, const char *, const struct tm *) = strftime;
 	size_t ret;

@@ -1404,6 +1407,7 @@ size_t mingw_strftime(char *s, size_t max,
 		ret = strftime(s, max, format, tm);
 	else
 		ret = fallback(s, max, format, tm);
+#endif
 
 	if (!ret && errno == EINVAL)
 		die("invalid strftime format: '%s'", format);

base-commit: 6e8d538aab8fe4dd07ba9fb87b5c7edcfa5706ad

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