[glib: 1/8] gio: icons should fallback to non-preferred style appropriately.

[Philip Withnall <pwithnall src gnome org>]

commit e0f2671a4adca4b09bd84de186955d13a090ff49
Author: Jehan <jehan girinstud io>
Date:   Thu Jun 7 01:54:36 2018 +0200

    gio: icons should fallback to non-preferred style appropriately.
    
    Whatever the preferred icon style is (symbolic, regular or the requested
    style), fallbacking to the other style in case of absent variant is
    better than not finding any icon at all.
    Also style fallbacking should be managed separately from property
    "use-default-fallbacks". Default fallbacks are meant for the process of
    getting up in context levels (as separated by dashes in icon name). Even
    though it also uses dash characters in format, this is a different
    concept as the variant of styles.
    
    Without this commit for instance, if an icon only had a symbolic
    variant, and the theme had "-gtk-icon-style" set to "regular" while your
    GTK+ application requested the regular icon name, you were getting no
    icons, and the application would look completely broken.
    Now one would at least fallback to the symbolic icon as last resort
    (which is infinitely better than having no icons).

 gio/gthemedicon.c | 58 +++++++++++++++++++++++++++++++------------------------
 1 file changed, 33 insertions(+), 25 deletions(-)
---
diff --git a/gio/gthemedicon.c b/gio/gthemedicon.c
index 3ada77b6c..71a692bd2 100644
--- a/gio/gthemedicon.c
+++ b/gio/gthemedicon.c
@@ -143,25 +143,27 @@ g_themed_icon_set_property (GObject      *object,
 static void
 g_themed_icon_constructed (GObject *object)
 {
-  GThemedIcon *themed = G_THEMED_ICON (object);
+  GThemedIcon  *themed = G_THEMED_ICON (object);
+  gchar       **names;
+  gchar        *name;
+  gboolean      is_symbolic;
+  gint          i = 0;
+  gint          n_names;
 
   g_return_if_fail (themed->names != NULL && themed->names[0] != NULL);
 
+  is_symbolic = g_str_has_suffix (themed->names[0], "-symbolic");
+  if (is_symbolic)
+    name = g_strndup (themed->names[0], strlen (themed->names[0]) - 9);
+  else
+    name = g_strdup (themed->names[0]);
+
   if (themed->use_default_fallbacks)
     {
-      int i = 0, dashes = 0;
+      int dashes = 0;
       const char *p;
       char *dashp;
       char *last;
-      gboolean is_symbolic;
-      char *name;
-      char **names;
-
-      is_symbolic = g_str_has_suffix (themed->names[0], "-symbolic");
-      if (is_symbolic)
-        name = g_strndup (themed->names[0], strlen (themed->names[0]) - 9);
-      else
-        name = g_strdup (themed->names[0]);
 
       p = name;
       while (*p)
@@ -173,33 +175,39 @@ g_themed_icon_constructed (GObject *object)
 
       last = name;
 
-      g_strfreev (themed->names);
-
       names = g_new (char *, dashes + 1 + 1);
       names[i++] = last;
 
       while ((dashp = strrchr (last, '-')) != NULL)
         names[i++] = last = g_strndup (last, dashp - last);
+    }
+  else
+    {
+      names = g_new (char *, 2);
+      names[i++] = name;
+    }
+  names[i] = NULL;
+  n_names = i;
+  g_strfreev (themed->names);
 
-      names[i++] = NULL;
-
+  /* All icons must be searched in symbolic and regular form. */
+  themed->names = g_new (char *, 2 * n_names + 1);
+  for (i = 0; names[i] != NULL; i++)
+    {
       if (is_symbolic)
         {
-          themed->names = g_new (char *, 2 * dashes + 3);
-          for (i = 0; names[i] != NULL; i++)
-            {
-              themed->names[i] = g_strconcat (names[i], "-symbolic", NULL);
-              themed->names[dashes + 1 + i] = names[i];
-            }
-
-          themed->names[dashes + 1 + i] = NULL;
-          g_free (names);
+          themed->names[i] = g_strconcat (names[i], "-symbolic", NULL);
+          themed->names[n_names + i] = names[i];
         }
       else
         {
-          themed->names = names;
+          themed->names[i] = names[i];
+          themed->names[n_names + i] = g_strconcat (names[i], "-symbolic", NULL);
         }
     }
+  themed->names[2 * n_names] = NULL;
+
+  g_free (names);
 }
 
 static void