css: Fix up incomplete resolve plumbing

I didn't quite get it right for all our image subtypes at first.

Fixes: #6814

gtk/gtkcssimagecrossfade.c

@@ -448,6 +448,49 @@ gtk_css_image_cross_fade_is_computed (GtkCssImage *image)
   return TRUE;
 }
 
+static gboolean
+gtk_css_image_cross_fade_contains_current_color (GtkCssImage *image)
+{
+  GtkCssImageCrossFade *cross_fade = GTK_CSS_IMAGE_CROSS_FADE (image);
+  guint i;
+
+  for (i = 0; i < cross_fade->images->len; i++)
+    {
+      const CrossFadeEntry *entry = &g_array_index (cross_fade->images, CrossFadeEntry, i);
+      if (gtk_css_image_contains_current_color (entry->image))
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
+static GtkCssImage *
+gtk_css_image_cross_fade_resolve (GtkCssImage          *image,
+                                  GtkCssComputeContext *context,
+                                  GtkCssValue          *current)
+{
+  GtkCssImageCrossFade *self = GTK_CSS_IMAGE_CROSS_FADE (image);
+  GtkCssImageCrossFade *result;
+  guint i;
+
+  if (!gtk_css_image_cross_fade_contains_current_color (image))
+    return g_object_ref (image);
+
+  result = gtk_css_image_cross_fade_new_empty ();
+
+  for (i = 0; i < self->images->len; i++)
+    {
+      CrossFadeEntry *entry = &g_array_index (self->images, CrossFadeEntry, i);
+
+      gtk_css_image_cross_fade_add (result,
+                                    entry->has_progress,
+                                    entry->progress,
+                                    gtk_css_image_resolve (entry->image, context, current));
+    }
+
+  return GTK_CSS_IMAGE (result);
+}
+
 static void
 gtk_css_image_cross_fade_class_init (GtkCssImageCrossFadeClass *klass)
 {
@@ -464,6 +507,8 @@ gtk_css_image_cross_fade_class_init (GtkCssImageCrossFadeClass *klass)
   image_class->parse = gtk_css_image_cross_fade_parse;
   image_class->print = gtk_css_image_cross_fade_print;
   image_class->is_computed = gtk_css_image_cross_fade_is_computed;
+  image_class->contains_current_color = gtk_css_image_cross_fade_contains_current_color;
+  image_class->resolve = gtk_css_image_cross_fade_resolve;
 
   object_class->dispose = gtk_css_image_cross_fade_dispose;
 }

gtk/gtkcssimagefallback.c

@@ -323,7 +323,7 @@ gtk_css_image_fallback_contains_current_color (GtkCssImage *image)
         }
     }
 
-  return FALSE;
+  return gtk_css_image_contains_current_color (fallback->images[fallback->used]);
 }
 
 static GtkCssImage *
@@ -335,6 +335,9 @@ gtk_css_image_fallback_resolve (GtkCssImage          *image,
   GtkCssImageFallback *resolved;
   int i;
 
+  if (!gtk_css_image_fallback_contains_current_color (image))
+    return g_object_ref (image);
+
   if (fallback->used < 0)
     {
       GtkCssValue *resolved_color = NULL;
@@ -351,7 +354,7 @@ gtk_css_image_fallback_resolve (GtkCssImage          *image,
       resolved->images = g_new (GtkCssImage *, fallback->n_images);
       for (i = 0; i < fallback->n_images; i++)
         {
-          resolved->images[i] = g_object_ref (fallback->images[i]);
+          resolved->images[i] = gtk_css_image_resolve (fallback->images[i], context, current_color);
 
           if (gtk_css_image_is_invalid (resolved->images[i]))
             continue;
@@ -365,7 +368,7 @@ gtk_css_image_fallback_resolve (GtkCssImage          *image,
       return GTK_CSS_IMAGE (resolved);
     }
   else
-    return GTK_CSS_IMAGE (g_object_ref (image));
+    return gtk_css_image_resolve (fallback->images[fallback->used], context, current_color);
 }
 
 static void

gtk/gtkcssimagelinear.c

@@ -772,6 +772,9 @@ gtk_css_image_linear_resolve (GtkCssImage          *image,
   GtkCssImageLinear *copy;
   guint i;
 
+  if (!gtk_css_image_linear_contains_current_color (image))
+    return g_object_ref (image);
+
   copy = g_object_new (GTK_TYPE_CSS_IMAGE_LINEAR, NULL);
   copy->repeating = linear->repeating;
   copy->side = linear->side;

gtk/gtkcssimagepaintable.c

@@ -157,6 +157,20 @@ gtk_css_image_paintable_is_computed (GtkCssImage *image)
   return (gdk_paintable_get_flags (self->paintable) & GDK_PAINTABLE_IMMUTABLE) == GDK_PAINTABLE_IMMUTABLE;
 }
 
+static gboolean
+gtk_css_image_paintable_contains_current_color (GtkCssImage *image)
+{
+  return FALSE;
+}
+
+static GtkCssImage *
+gtk_css_image_paintable_resolve (GtkCssImage          *image,
+                                 GtkCssComputeContext *context,
+                                 GtkCssValue          *value)
+{
+  return g_object_ref (image);
+}
+
 static void
 gtk_css_image_paintable_class_init (GtkCssImagePaintableClass *klass)
 {
@@ -173,6 +187,8 @@ gtk_css_image_paintable_class_init (GtkCssImagePaintableClass *klass)
   image_class->is_dynamic = gtk_css_image_paintable_is_dynamic;
   image_class->is_computed = gtk_css_image_paintable_is_computed;
   image_class->get_dynamic_image = gtk_css_image_paintable_get_dynamic_image;
+  image_class->contains_current_color = gtk_css_image_paintable_contains_current_color;
+  image_class->resolve = gtk_css_image_paintable_resolve;
 
   object_class->dispose = gtk_css_image_paintable_dispose;
 }

gtk/gtkcssimageradial.c

@@ -773,6 +773,9 @@ gtk_css_image_radial_resolve (GtkCssImage          *image,
   GtkCssImageRadial *radial = GTK_CSS_IMAGE_RADIAL (image);
   GtkCssImageRadial *copy;
 
+  if (!gtk_css_image_radial_contains_current_color (image))
+    return g_object_ref (image);
+
   copy = g_object_new (GTK_TYPE_CSS_IMAGE_RADIAL, NULL);
   copy->repeating = radial->repeating;
   copy->circle = radial->circle;

gtk/gtkcssimagescaled.c

@@ -230,6 +230,9 @@ gtk_css_image_scaled_resolve (GtkCssImage          *image,
   GtkCssImageScaled *self = GTK_CSS_IMAGE_SCALED (image);
   GtkCssImageScaled *res;
 
+  if (!gtk_css_image_scaled_contains_current_color (image))
+    return g_object_ref (image);
+
   res = g_object_new (GTK_TYPE_CSS_IMAGE_SCALED, NULL);
 
   res->n_images = self->n_images;

gtk/gtkcssimageurl.c

@@ -159,6 +159,21 @@ gtk_css_image_url_is_computed (GtkCssImage *image)
   return TRUE;
 }
 
+static GtkCssImage *
+gtk_css_image_url_resolve (GtkCssImage          *image,
+                           GtkCssComputeContext *context,
+                           GtkCssValue          *current)
+{
+  return g_object_ref (image);
+}
+
+static gboolean
+gtk_css_image_url_contains_current_color (GtkCssImage *image)
+{
+  return FALSE;
+}
+
+
 static gboolean
 gtk_css_image_url_parse (GtkCssImage  *image,
                          GtkCssParser *parser)
@@ -253,6 +268,8 @@ _gtk_css_image_url_class_init (GtkCssImageUrlClass *klass)
   image_class->equal = gtk_css_image_url_equal;
   image_class->is_invalid = gtk_css_image_url_is_invalid;
   image_class->is_computed = gtk_css_image_url_is_computed;
+  image_class->contains_current_color = gtk_css_image_url_contains_current_color;
+  image_class->resolve = gtk_css_image_url_resolve;
 
   object_class->dispose = gtk_css_image_url_dispose;
 }