compat UPDATE add timegm to compat

Author: roman

CMakeModules/UseCompat.cmake

@@ -62,6 +62,8 @@ macro(USE_COMPAT)
 
     check_symbol_exists(get_current_dir_name "unistd.h" HAVE_GET_CURRENT_DIR_NAME)
 
+    check_function_exists(timegm HAVE_TIMEGM)
+
     # crypt
     check_include_file("crypt.h" HAVE_CRYPT_H)
 

compat/compat.c

@@ -391,3 +391,37 @@ crypt_r(const char *phrase, const char *setting, struct crypt_data *data)
 }
 
 #endif
+
+#ifndef HAVE_TIMEGM
+time_t
+timegm(struct tm *tm)
+{
+    pthread_mutex_t tz_lock = PTHREAD_MUTEX_INITIALIZER;
+    time_t ret;
+    char *tz;
+
+    pthread_mutex_lock(&tz_lock);
+
+    tz = getenv("TZ");
+    if (tz) {
+        tz = strdup(tz);
+    }
+    setenv("TZ", "", 1);
+    tzset();
+
+    ret = mktime(tm);
+
+    if (tz) {
+        setenv("TZ", tz, 1);
+        free(tz);
+    } else {
+        unsetenv("TZ");
+    }
+    tzset();
+
+    pthread_mutex_unlock(&tz_lock);
+
+    return ret;
+}
+
+#endif

compat/compat.h.in

@@ -77,6 +77,7 @@
 #cmakedefine HAVE_STRCHRNUL
 #cmakedefine HAVE_GET_CURRENT_DIR_NAME
 #cmakedefine HAVE_CRYPT_R
+#cmakedefine HAVE_TIMEGM
 
 #ifndef bswap64
 #define bswap64(val) \
@@ -222,4 +223,8 @@ struct crypt_data {
 char *crypt_r(const char *phrase, const char *setting, struct crypt_data *data);
 #endif
 
+#ifndef HAVE_TIMEGM
+time_t timegm(struct tm *tm);
+#endif
+
 #endif /* _COMPAT_H_ */