ico: Fix support for 256x256 icons

In both loading and saving them. The ico format uses "0" as the width
or height to mean 256:
https://en.wikipedia.org/wiki/ICO_%28file_format%29#Icon_resource_structure

Also add a test for that.

https://bugzilla.gnome.org/show_bug.cgi?id=674724

2 files changed, 34 insertions, 1 deletions

diff --git a/tests/pixbuf-save.c b/tests/pixbuf-save.c
index 72a7aea4b..61ef07baf 100644
--- a/tests/pixbuf-save.c
+++ b/tests/pixbuf-save.c
@@ -98,6 +98,38 @@ test_save_roundtrip (void)
 }
 
 static void
+test_save_ico (void)
+{
+  GError *error = NULL;
+  GdkPixbuf *ref, *ref2;
+  GdkPixbuf *pixbuf;
+
+  if (!format_supported ("ico") || !format_supported ("png"))
+    {
+      g_test_skip ("format not supported");
+      return;
+    }
+
+  ref = gdk_pixbuf_new_from_file (g_test_get_filename (G_TEST_DIST, "test-image.png", NULL), &error);
+  g_assert_no_error (error);
+
+  ref2 = gdk_pixbuf_scale_simple (ref, 256, 256, GDK_INTERP_NEAREST);
+  g_object_unref (ref);
+  ref = ref2;
+
+  gdk_pixbuf_save (ref, "pixbuf-save-roundtrip", "ico", &error, NULL);
+  g_assert_no_error (error);
+
+  pixbuf = gdk_pixbuf_new_from_file ("pixbuf-save-roundtrip", &error);
+  g_assert_no_error (error);
+
+  g_assert (pixbuf_equal (pixbuf, ref));
+
+  g_object_unref (pixbuf);
+  g_object_unref (ref);
+}
+
+static void
 test_save_options (void)
 {
   GdkPixbuf *ref;
@@ -142,6 +174,7 @@ main (int argc, char **argv)
 
   g_test_add_func ("/pixbuf/save/roundtrip", test_save_roundtrip);
   g_test_add_func ("/pixbuf/save/options", test_save_options);
+  g_test_add_func ("/pixbuf/save/ico", test_save_ico);
 
   return g_test_run ();
 }
diff --git a/tests/test-common.c b/tests/test-common.c
index c7673e395..a7107a114 100644
--- a/tests/test-common.c
+++ b/tests/test-common.c
@@ -33,7 +33,7 @@ format_supported (const gchar *filename)
   GSList *formats, *l;
   gboolean retval;
   const gchar *names[] = { "png", "jpeg", "bmp", "gif", "ras",
-    "tga", "xpm", "xbm" };
+    "tga", "xpm", "xbm", "ico" };
   gint i;
 
   for (i = 0; i < G_N_ELEMENTS (names); i++)