Use reentrant versions of datetime functions for thread safety

1 files changed, 30 insertions, 27 deletions

diff --git a/src/jpeg-utils.cpp b/src/jpeg-utils.cpp
index c9c080d..6af7f1f 100644
--- a/src/jpeg-utils.cpp
+++ b/src/jpeg-utils.cpp
@@ -39,7 +39,6 @@ static void
 shift_time (struct tm *tm, int offset_min)
 {
   time_t t;
-  struct tm *new_t;
 
   if (offset_min != 0) {
     /*  FIXME: converting between time formats could make some data lost, better to operate over struct tm directly  */
@@ -51,8 +50,7 @@ shift_time (struct tm *tm, int offset_min)
 
     t += offset_min * 60;
 
-    new_t = localtime (&t);
-    memcpy (tm, new_t, sizeof (struct tm));
+    localtime_r (&t, tm);
   }
 }
 
@@ -246,26 +244,31 @@ get_exif_data_fixed (ExifData *exif, const gchar *key)
           } catch (...) { }
 
         if (val && strlen (val) > 0) {
-          struct tm *tt;
+          struct tm *tt = NULL;
           char conv[1024];
+          gchar *res = NULL;
 
           memset (&conv, 0, sizeof (conv));
 
           if (exif->fake_datetime != (time_t) -1) {
-            tt = localtime (&exif->fake_datetime);
+            tt = (struct tm *) g_malloc0 (sizeof (struct tm));
+            localtime_r (&exif->fake_datetime, tt);
             if (strftime (&conv[0], sizeof (conv), "%c", tt))
-              return g_strdup (&conv[0]);
+              res = g_strdup (&conv[0]);
           }
 
-          tt = parse_exif_date (val);
-          if (tt) {
-            shift_time (tt, exif->timezone_shift);
-            if (strftime (&conv[0], sizeof (conv), "%c", tt)) {
-              g_free (tt);
-              return g_strdup (&conv[0]);
+          if (! res) {
+            tt = parse_exif_date (val);
+            if (tt) {
+              shift_time (tt, exif->timezone_shift);
+              if (strftime (&conv[0], sizeof (conv), "%c", tt))
+                res = g_strdup (&conv[0]);
             }
-            g_free (tt);
           }
+
+          g_free (tt);
+          if (res)
+            return res;
         }
       }
 
@@ -579,7 +582,7 @@ shift_exif_time (Exiv2::ExifData& exifData, const char *key, int amount)
 static gboolean
 shift_iptc_time (Exiv2::IptcData &iptcData, int amount)
 {
-  struct tm *tt;
+  struct tm tt = {0};
   long int orig_time;
   gboolean res;
   Exiv2::DateValue dval;
@@ -592,13 +595,13 @@ shift_iptc_time (Exiv2::IptcData &iptcData, int amount)
                 (iptc_has_key (iptcData, "Iptc.Application2.TimeCreated") ? iptcData["Iptc.Application2.TimeCreated"].toLong() : 0);
     if (orig_time > 0) {
       orig_time += amount * 60;
-      tt = localtime (&orig_time);
-      mktime (tt);
-      if (tt->tm_isdst)
-        shift_time (tt, -60);
+      localtime_r (&orig_time, &tt);
+      mktime (&tt);
+      if (tt.tm_isdst)
+        shift_time (&tt, -60);
 
-      dval = Exiv2::DateValue(tt->tm_year + 1900, tt->tm_mon + 1, tt->tm_mday);
-      tval = Exiv2::TimeValue(tt->tm_hour, tt->tm_min, tt->tm_sec, 0, 0);
+      dval = Exiv2::DateValue(tt.tm_year + 1900, tt.tm_mon + 1, tt.tm_mday);
+      tval = Exiv2::TimeValue(tt.tm_hour, tt.tm_min, tt.tm_sec, 0, 0);
       iptcData["Iptc.Application2.DateCreated"].setValue(&dval);
       iptcData["Iptc.Application2.TimeCreated"].setValue(&tval);
       res = TRUE;
@@ -611,15 +614,15 @@ shift_iptc_time (Exiv2::IptcData &iptcData, int amount)
 static gboolean
 fake_exif_time (Exiv2::ExifData &exifData, const char *key, time_t datetime)
 {
-  struct tm *tt;
+  struct tm tt = {0};
   gchar *st;
   gboolean res;
 
   res = FALSE;
   try {
     if (exifData[key].count() > 0) {
-      tt = localtime (&datetime);
-      st = format_exif_time (tt);
+      localtime_r (&datetime, &tt);
+      st = format_exif_time (&tt);
       if (st)
         exifData[key] = st;
       g_free (st);
@@ -633,14 +636,14 @@ fake_exif_time (Exiv2::ExifData &exifData, const char *key, time_t datetime)
 static void
 fake_iptc_time (Exiv2::IptcData &iptcData, time_t datetime)
 {
-  struct tm *tt;
+  struct tm tt = {0};
   Exiv2::DateValue dval;
   Exiv2::TimeValue tval;
 
-  tt = localtime (&datetime);
+  localtime_r (&datetime, &tt);
 
-  dval = Exiv2::DateValue(tt->tm_year + 1900, tt->tm_mon + 1, tt->tm_mday);
-  tval = Exiv2::TimeValue(tt->tm_hour, tt->tm_min, tt->tm_sec, 0, 0);
+  dval = Exiv2::DateValue(tt.tm_year + 1900, tt.tm_mon + 1, tt.tm_mday);
+  tval = Exiv2::TimeValue(tt.tm_hour, tt.tm_min, tt.tm_sec, 0, 0);
   iptcData["Iptc.Application2.DateCreated"].setValue(&dval);
   iptcData["Iptc.Application2.TimeCreated"].setValue(&tval);
 }