icon-info: hash/store icons using scale factor as well as size

Otherwise we might pick up an icon at an invalid size for a given scale.

https://bugzilla.gnome.org/show_bug.cgi?id=776896

origin commit:
https://gitlab.gnome.org/GNOME/nautilus/commit/53cee1de

libcaja-private/caja-icon-info.c

@@ -186,12 +186,14 @@ caja_icon_info_new_for_icon_info (GtkIconInfo *icon_info,
 typedef struct
 {
     GIcon *icon;
+    int scale;
     int size;
 } LoadableIconKey;
 
 typedef struct
 {
     char *filename;
+    int scale;
     int size;
 } ThemedIconKey;
 
@@ -290,24 +292,28 @@ caja_icon_info_clear_caches (void)
 static guint
 loadable_icon_key_hash (LoadableIconKey *key)
 {
-    return g_icon_hash (key->icon) ^ key->size;
+    return g_icon_hash (key->icon) ^ key->scale ^ key->size;
 }
 
 static gboolean
 loadable_icon_key_equal (const LoadableIconKey *a,
                          const LoadableIconKey *b)
 {
     return a->size == b->size &&
+           a->scale == b->scale &&
            g_icon_equal (a->icon, b->icon);
 }
 
 static LoadableIconKey *
-loadable_icon_key_new (GIcon *icon, int size)
+loadable_icon_key_new (GIcon *icon,
+                       int    scale,
+                       int    size)
 {
     LoadableIconKey *key;
 
     key = g_slice_new (LoadableIconKey);
     key->icon = g_object_ref (icon);
+    key->scale = scale;
     key->size = size;
 
     return key;
@@ -331,16 +337,20 @@ themed_icon_key_equal (const ThemedIconKey *a,
                        const ThemedIconKey *b)
 {
     return a->size == b->size &&
+           a->scale == b->scale &&
            g_str_equal (a->filename, b->filename);
 }
 
 static ThemedIconKey *
-themed_icon_key_new (const char *filename, int size)
+themed_icon_key_new (const char *filename,
+                     int         scale,
+                     int         size)
 {
     ThemedIconKey *key;
 
     key = g_slice_new (ThemedIconKey);
     key->filename = g_strdup (filename);
+    key->scale = scale;
     key->size = size;
 
     return key;
@@ -377,7 +387,8 @@ caja_icon_info_lookup (GIcon *icon,
         }
 
         lookup_key.icon = icon;
-        lookup_key.size = size;
+        lookup_key.scale = scale;
+        lookup_key.size = size * scale;
 
         icon_info = g_hash_table_lookup (loadable_icon_cache, &lookup_key);
         if (icon_info)
@@ -401,7 +412,7 @@ caja_icon_info_lookup (GIcon *icon,
 
         icon_info = caja_icon_info_new_for_pixbuf (pixbuf, scale);
 
-        key = loadable_icon_key_new (icon, size);
+        key = loadable_icon_key_new (icon, scale, size);
         g_hash_table_insert (loadable_icon_cache, key, icon_info);
 
         return g_object_ref (icon_info);
@@ -442,6 +453,7 @@ caja_icon_info_lookup (GIcon *icon,
         }
 
         lookup_key.filename = (char *)filename;
+        lookup_key.scale = scale;
         lookup_key.size = size;
 
         icon_info = g_hash_table_lookup (themed_icon_cache, &lookup_key);
@@ -453,7 +465,7 @@ caja_icon_info_lookup (GIcon *icon,
 
         icon_info = caja_icon_info_new_for_icon_info (gtkicon_info, scale);
 
-        key = themed_icon_key_new (filename, size);
+        key = themed_icon_key_new (filename, scale, size);
         g_hash_table_insert (themed_icon_cache, key, icon_info);
 
         g_object_unref (gtkicon_info);