thumbnails: Check original file for modifications.

1 files changed, 29 insertions, 4 deletions

diff --git a/thumbnails.c b/thumbnails.c
index 19cc817..83e6ec4 100644
--- a/thumbnails.c
+++ b/thumbnails.c
@@ -31,6 +31,26 @@ inline static time_t get_mtime(const gchar *filepath) {
 	}
 }
 
+inline static gboolean is_thumb_modified(GdkPixbuf *pb, const gchar *filename, const gchar *thumbname) {
+	time_t mtime, pb_mtime, thumb_mtime;
+	const gchar *mtime_s;
+
+	mtime = get_mtime(filename);
+	mtime_s = gdk_pixbuf_get_option(pb, "tEXt::Thumb::MTime");
+	pb_mtime = g_ascii_strtoll(mtime_s, NULL, 10);
+
+	/* Original file modified since thumbnail creation. */
+	if(mtime != pb_mtime)
+		return TRUE;
+
+	thumb_mtime = get_mtime(thumbname);
+	/* Original file newer than thumbnail. */
+	if(mtime > thumb_mtime)
+		return TRUE;
+
+	return FALSE;
+}
+
 GdkPixbuf *get_thumbnail(const gchar *filepath) {
 	GdkPixbuf *pb, *pb2;
 	gint win_width, win_height, img_width, img_height, width, height;
@@ -42,15 +62,20 @@ GdkPixbuf *get_thumbnail(const gchar *filepath) {
 
 	if(g_access(thumbname, F_OK) == 0) {
 		pb = gdk_pixbuf_new_from_file(thumbname, &error);
-		g_free(thumbname);
-		return pb;
-	} else {
-		pb = gdk_pixbuf_new_from_file(filepath, &error);
+		if(pb && !is_thumb_modified(pb, filepath, thumbname)) {
+			g_free(thumbname);
+			return pb;
+		} else if(pb) {
+			g_object_unref(pb);
+		}
 	}
 
+	pb = gdk_pixbuf_new_from_file(filepath, &error);
+
 	if(!pb) {
 		g_warning("%s", error->message);
 		g_free(error);
+		g_free(thumbname);
 		return NULL;
 	}