Merge branch 'jk/commit-dates-parsing-fix' into maint

* jk/commit-dates-parsing-fix:
  t4212: loosen far-in-future test for AIX
  date: recognize bogus FreeBSD gmtime output

Makefile

@@ -342,6 +342,9 @@ all::
 # Define DEFAULT_HELP_FORMAT to "man", "info" or "html"
 # (defaults to "man") if you want to have a different default when
 # "git help" is called without a parameter specifying the format.
+#
+# Define GMTIME_UNRELIABLE_ERRORS if your gmtime() function does not
+# return NULL when it receives a bogus time_t.
 
 GIT-VERSION-FILE: FORCE
 	@$(SHELL_PATH) ./GIT-VERSION-GEN
@@ -1494,6 +1497,11 @@ ifneq (,$(XDL_FAST_HASH))
 	BASIC_CFLAGS += -DXDL_FAST_HASH
 endif
 
+ifdef GMTIME_UNRELIABLE_ERRORS
+	COMPAT_OBJS += compat/gmtime.o
+	BASIC_CFLAGS += -DGMTIME_UNRELIABLE_ERRORS
+endif
+
 ifeq ($(TCLTK_PATH),)
 NO_TCLTK = NoThanks
 endif

compat/gmtime.c

@@ -0,0 +1,29 @@
+#include "../git-compat-util.h"
+#undef gmtime
+#undef gmtime_r
+
+struct tm *git_gmtime(const time_t *timep)
+{
+	static struct tm result;
+	return git_gmtime_r(timep, &result);
+}
+
+struct tm *git_gmtime_r(const time_t *timep, struct tm *result)
+{
+	struct tm *ret;
+
+	memset(result, 0, sizeof(*result));
+	ret = gmtime_r(timep, result);
+
+	/*
+	 * Rather than NULL, FreeBSD gmtime simply leaves the "struct tm"
+	 * untouched when it encounters overflow. Since "mday" cannot otherwise
+	 * be zero, we can test this very quickly.
+	 */
+	if (ret && !ret->tm_mday) {
+		ret = NULL;
+		errno = EOVERFLOW;
+	}
+
+	return ret;
+}

config.mak.uname

@@ -188,6 +188,7 @@ ifeq ($(uname_S),FreeBSD)
 	endif
 	PYTHON_PATH = /usr/local/bin/python
 	HAVE_PATHS_H = YesPlease
+	GMTIME_UNRELIABLE_ERRORS = UnfortunatelyYes
 endif
 ifeq ($(uname_S),OpenBSD)
 	NO_STRCASESTR = YesPlease

git-compat-util.h

@@ -721,4 +721,11 @@ void warn_on_inaccessible(const char *path);
 /* Get the passwd entry for the UID of the current process. */
 struct passwd *xgetpwuid_self(void);
 
+#ifdef GMTIME_UNRELIABLE_ERRORS
+struct tm *git_gmtime(const time_t *);
+struct tm *git_gmtime_r(const time_t *, struct tm *);
+#define gmtime git_gmtime
+#define gmtime_r git_gmtime_r
+#endif
+
 #endif

t/t4212-log-corrupt.sh

@@ -82,11 +82,9 @@ test_expect_success 'date parser recognizes time_t overflow' '
 '
 
 # date is within 2^63-1, but enough to choke glibc's gmtime
-test_expect_success 'absurdly far-in-future dates produce sentinel' '
+test_expect_success 'absurdly far-in-future date' '
 	commit=$(munge_author_date HEAD 999999999999999999) &&
-	echo "Thu Jan 1 00:00:00 1970 +0000" >expect &&
-	git log -1 --format=%ad $commit >actual &&
-	test_cmp expect actual
+	git log -1 --format=%ad $commit
 '
 
 test_done