jpeg: Add support for JPEG_COM EXIF tag

https://bugzilla.gnome.org/show_bug.cgi?id=143608

4 files changed, 53 insertions, 0 deletions

diff --git a/gdk-pixbuf/gdk-pixbuf.c b/gdk-pixbuf/gdk-pixbuf.c
index d7b78e4e2..fb146ba8d 100644
--- a/gdk-pixbuf/gdk-pixbuf.c
+++ b/gdk-pixbuf/gdk-pixbuf.c
@@ -909,6 +909,8 @@ gdk_pixbuf_fill (GdkPixbuf *pixbuf,
  * the "multipage" option string to "yes" when a multi-page TIFF is loaded.
  * Since 2.32 the JPEG and PNG loaders set "x-dpi" and "y-dpi" if the file
  * contains image density information in dots per inch.
+ * Since 2.36.6, the JPEG loader sets the "comment" option with the comment
+ * EXIF tag.
  * 
  * Return value: the value associated with @key. This is a nul-terminated 
  * string that should not be freed or %NULL if @key was not found.
diff --git a/gdk-pixbuf/io-jpeg.c b/gdk-pixbuf/io-jpeg.c
index 92ec36b47..dd88a350a 100644
--- a/gdk-pixbuf/io-jpeg.c
+++ b/gdk-pixbuf/io-jpeg.c
@@ -525,6 +525,21 @@ jpeg_parse_exif (JpegExifContext *context, j_decompress_ptr cinfo)
 	}
 }
 
+static gchar *
+jpeg_get_comment (j_decompress_ptr cinfo)
+{
+	jpeg_saved_marker_ptr cmarker;
+
+	cmarker = cinfo->marker_list;
+	while (cmarker != NULL) {
+		if (cmarker->marker == JPEG_COM)
+			return g_strndup ((const gchar *) cmarker->data, cmarker->data_length);
+		cmarker = cmarker->next;
+	}
+
+	return NULL;
+}
+
 static void
 jpeg_destroy_exif_context (JpegExifContext *context)
 {
@@ -550,6 +565,7 @@ gdk_pixbuf__jpeg_image_load (FILE *f, GError **error)
 	struct error_handler_data jerr;
 	stdio_src_ptr src;
 	gchar *icc_profile_base64;
+	gchar *comment;
 	JpegExifContext exif_context = { 0, };
 
 	/* setup error handler */
@@ -592,6 +608,7 @@ gdk_pixbuf__jpeg_image_load (FILE *f, GError **error)
 
 	jpeg_save_markers (&cinfo, JPEG_APP0+1, 0xffff);
 	jpeg_save_markers (&cinfo, JPEG_APP0+2, 0xffff);
+	jpeg_save_markers (&cinfo, JPEG_COM, 0xffff);
 	jpeg_read_header (&cinfo, TRUE);
 
 	/* parse exif data */
@@ -619,6 +636,12 @@ gdk_pixbuf__jpeg_image_load (FILE *f, GError **error)
 		goto out; 
 	}
 
+	comment = jpeg_get_comment (&cinfo);
+	if (comment != NULL) {
+		gdk_pixbuf_set_option (pixbuf, "comment", comment);
+		g_free (comment);
+	}
+
 	switch (cinfo.density_unit) {
 	case 1:
 		/* Dots per inch (no conversion required) */
@@ -1027,9 +1050,11 @@ gdk_pixbuf__jpeg_image_load_increment (gpointer data,
 		/* try to load jpeg header */
 		if (!context->got_header) {
 			int rc;
+			gchar* comment;
 		
 			jpeg_save_markers (cinfo, JPEG_APP0+1, 0xffff);
 			jpeg_save_markers (cinfo, JPEG_APP0+2, 0xffff);
+			jpeg_save_markers (cinfo, JPEG_COM, 0xffff);
 			rc = jpeg_read_header (cinfo, TRUE);
 			context->src_initialized = TRUE;
 			
@@ -1080,6 +1105,12 @@ gdk_pixbuf__jpeg_image_load_increment (gpointer data,
 				goto out;
 			}
 
+			comment = jpeg_get_comment (cinfo);
+			if (comment != NULL) {
+				gdk_pixbuf_set_option (context->pixbuf, "comment", comment);
+				g_free (comment);
+			}
+
 			switch (cinfo->density_unit) {
 			case 1:
 				/* Dots per inch (no conversion required) */
diff --git a/tests/bug143608-comment.jpg b/tests/bug143608-comment.jpg
new file mode 100644
index 000000000..7c3c93a71
--- /dev/null
+++ b/tests/bug143608-comment.jpg
diff --git a/tests/pixbuf-jpeg.c b/tests/pixbuf-jpeg.c
index 073104a32..ea1d62eae 100644
--- a/tests/pixbuf-jpeg.c
+++ b/tests/pixbuf-jpeg.c
@@ -96,6 +96,25 @@ test_bug_775218 (void)
   g_clear_object (&ref);
 }
 
+static void
+test_comment(void)
+{
+  GError *error = NULL;
+  GdkPixbuf *ref;
+
+  if (!format_supported ("jpeg") || !format_supported ("png"))
+    {
+      g_test_skip ("format not supported");
+      return;
+    }
+
+  ref = gdk_pixbuf_new_from_file (g_test_get_filename (G_TEST_DIST, "bug143608-comment.jpg", NULL), &error);
+  g_assert_no_error (error);
+
+  g_assert_cmpstr (gdk_pixbuf_get_option (ref, "comment"), ==, "COMMENT HERE");
+  g_object_unref (ref);
+}
+
 int
 main (int argc, char **argv)
 {
@@ -104,6 +123,7 @@ main (int argc, char **argv)
   g_test_add_func ("/pixbuf/jpeg/inverted_cmyk_jpeg", test_inverted_cmyk_jpeg);
   g_test_add_func ("/pixbuf/jpeg/type9_rotation_exif_tag", test_type9_rotation_exif_tag);
   g_test_add_func ("/pixbuf/jpeg/bug775218", test_bug_775218);
+  g_test_add_func ("/pixbuf/jpeg/comment", test_comment);
 
   return g_test_run ();
 }