gdi32: correct substitutions (take 2)

[Rafał Mużyło]

Corrected version of the previous patch.
This time I'm not adding a new helper function, just putting it in one
place.
Corrections:
- as oppossed to get_font_subst, reverse check can have more than one
  result, so changed to adjust all of them
- just in case a->a substitution would result, explicitly prevent that
(perhaps gdi32 handles it gracefully, but it's still redundant)

-------------- next part --------------
--- dlls/gdi32/freetype.c.old	2011-02-04 20:06:51.000000000 +0100
+++ dlls/gdi32/freetype.c	2011-02-14 21:11:25.556395305 +0100
@@ -949,7 +949,7 @@
 
 static BOOL add_font_subst(struct list *subst_list, FontSubst *subst, INT flags)
 {
-    FontSubst *from_exist, *to_exist;
+    FontSubst *from_exist, *to_exist, *reverse_to;
 
     from_exist = get_font_subst(subst_list, subst->from.name, subst->from.charset);
 
@@ -971,7 +971,26 @@
             HeapFree(GetProcessHeap(), 0, subst->to.name);
             subst->to.name = strdupW(to_exist->to.name);
         }
-            
+
+        LIST_FOR_EACH_ENTRY(reverse_to, subst_list, FontSubst, entry)
+        {
+            if(!strcmpiW(reverse_to->to.name, subst->from.name) &&
+               (reverse_to->to.charset == subst->from.charset ||
+                reverse_to->to.charset == -1))
+            {
+                list_remove(&reverse_to->entry);
+                HeapFree(GetProcessHeap(), 0, reverse_to->to.name);
+                if (strcmpiW(reverse_to->from.name, subst->to.name))
+                {
+                    reverse_to->to.name = strdupW(subst->to.name);
+                    list_add_tail(subst_list, &reverse_to->entry);
+                } else {
+                    HeapFree(GetProcessHeap(), 0, &reverse_to->from.name);
+                    HeapFree(GetProcessHeap(), 0, reverse_to);
+                }
+            }
+        }
+
         list_add_tail(subst_list, &subst->entry);
 
         return TRUE;