[Fix] Add workaround for system with non-XSI compatible tzset

CMakeLists.txt

@@ -920,6 +920,15 @@ CHECK_C_SOURCE_COMPILES(
 	int main(int argc, char** argv) {
   		return cmkcheckweak == NULL;
 	}" HAVE_WEAK_SYMBOLS)
+CHECK_C_SOURCE_COMPILES(
+		"#include <time.h>
+		extern char *tzname[2];
+		extern long timezone;
+		extern int daylight;
+	int main(int argc, char** argv) {
+		tzset();
+		return timezone;
+	}" HAVE_SANE_TZSET)
 
 IF(WITH_ICONV)
 	CHECK_C_SOURCE_COMPILES("

config.h.in

@@ -75,6 +75,7 @@
 #cmakedefine HAVE_READPASSPHRASE_H  1
 #cmakedefine HAVE_SA_SIGINFO     1
 #cmakedefine HAVE_SANE_SHMEM     1
+#cmakedefine HAVE_SANE_TZSET     1
 #cmakedefine HAVE_SCHED_YEILD    1
 #cmakedefine HAVE_SC_NPROCESSORS_ONLN 1
 #cmakedefine HAVE_SEARCH_H       1

src/libutil/util.c

@@ -2762,6 +2762,7 @@ rspamd_gmtime (gint64 ts, struct tm *dest)
 	dest->tm_zone = "GMT";
 }
 
+#ifdef HAVE_SANE_TZSET
 extern char *tzname[2];
 extern long timezone;
 extern int daylight;
@@ -2784,6 +2785,14 @@ void rspamd_localtime (gint64 ts, struct tm *dest)
 #endif
 }
 
+#else
+void rspamd_localtime (gint64 ts, struct tm *dest)
+{
+	time_t t = ts;
+	localtime_r (&t, dest);
+}
+#endif
+
 gboolean
 rspamd_fstring_gzip (rspamd_fstring_t **in)
 {