[AD] Memory leaks

["Trent Gamblin" <trent@xxxxxxxxxx>]

I found a good (Windows, Commercial) memory leak detector called "Memory Validator" and run my Allegro 5 game through
it. It found 6 or so memory leaks in Allegro. I looked at the first two and they are genuine leaks, and I haven't
checked the others out yet fully but they appear to be real leaks too. I will fix them shortly if I can, but the one
major one I am posting a patch for now. I think Milan made the font addon use subbitmaps so he can probably verify if
this is correct.

Index: addons/font/font.c
===================================================================
--- addons/font/font.c  (revision 12255)
+++ addons/font/font.c  (working copy)
@@ -190,8 +190,14 @@

         for(i = cf->begin; i < cf->end; i++) al_destroy_bitmap(cf->bitmaps[i - cf->begin]);
         /* Each range might point to the same bitmap. */
-        if (cf->glyphs != glyphs) al_destroy_bitmap(cf->glyphs);
+        if (cf->glyphs != glyphs) {
+            al_destroy_bitmap(cf->glyphs);
+            cf->glyphs = NULL;
+        }

+        if (!next && cf->glyphs)
+            al_destroy_bitmap(cf->glyphs);
+
         _AL_FREE(cf->bitmaps);
         _AL_FREE(cf);

Trent :{)>