Implement a font options compare function and use it in gstate

Valgrind is not happy with the memcmp() to compare font options and it
won't work correctly with variations and custom_palette.

3 files changed, 40 insertions, 1 deletions

diff --git a/src/cairo-font-options.c b/src/cairo-font-options.c
index 361882ae5..8876d9265 100644
--- a/src/cairo-font-options.c
+++ b/src/cairo-font-options.c
@@ -105,6 +105,41 @@ _cairo_font_options_init_copy (cairo_font_options_t		*options,
     }
 }
 
+cairo_bool_t
+_cairo_font_options_compare (const cairo_font_options_t	*a,
+                             const cairo_font_options_t	*b)
+{
+    if (a->antialias != b->antialias ||
+        a->subpixel_order != b->subpixel_order ||
+        a->lcd_filter != b->lcd_filter ||
+        a->hint_style != b->hint_style ||
+        a->hint_metrics != b->hint_metrics ||
+        a->round_glyph_positions != b->round_glyph_positions ||
+        a->color_mode != b->color_mode ||
+        a->palette_index != b->palette_index ||
+        a->custom_palette_size != b->custom_palette_size)
+    {
+        return FALSE;
+    }
+
+    if (a->variations && b->variations && strcmp (a->variations, b->variations) != 0)
+        return FALSE;
+    else if (a->variations != b->variations)
+        return FALSE;
+
+    if (a->custom_palette && b->custom_palette &&
+        memcmp (a->custom_palette, b->custom_palette, sizeof (cairo_palette_color_t) * a->custom_palette_size) != 0)
+    {
+        return FALSE;
+    }
+    else if (a->custom_palette != b->custom_palette)
+    {
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
 /**
  * cairo_font_options_create:
  *
diff --git a/src/cairo-gstate.c b/src/cairo-gstate.c
index 0f4fd541a..8a253468d 100644
--- a/src/cairo-gstate.c
+++ b/src/cairo-gstate.c
@@ -1748,7 +1748,7 @@ void
 _cairo_gstate_set_font_options (cairo_gstate_t             *gstate,
 				const cairo_font_options_t *options)
 {
-    if (memcmp (options, &gstate->font_options, sizeof (cairo_font_options_t)) == 0)
+    if (_cairo_font_options_compare (options, &gstate->font_options))
 	return;
 
     _cairo_gstate_unset_scaled_font (gstate);
diff --git a/src/cairoint.h b/src/cairoint.h
index 5ce747ee4..6682e4b30 100644
--- a/src/cairoint.h
+++ b/src/cairoint.h
@@ -897,6 +897,10 @@ cairo_private void
 _cairo_font_options_init_copy (cairo_font_options_t		*options,
 			       const cairo_font_options_t	*other);
 
+cairo_private cairo_bool_t
+_cairo_font_options_compare (const cairo_font_options_t	*a,
+                             const cairo_font_options_t	*b);
+
 cairo_private void
 _cairo_font_options_fini (cairo_font_options_t *options);