I have a question about this bit of the patch:

@@ -38,10 +38,31 @@
 #if defined(_RL_FUNCTION_TYPEDEF)
 extern char **completion_matches(char *, rl_compentry_func_t *);
 #else
+#if !defined(__APPLE__)
 extern char **completion_matches(char *, CPFunction *);
 #endif
 #endif
+#endif

That bit is not in the trunk, should it be forward ported to the trunk?

The actual prototype on 10.5 and 10.6 is:

char           **completion_matches(const char *, CPFunction *);

Wouldn't it be better to change the prototype in readline.c to match?

As that's not a critical change I've committed the fix1 patch as is in r78096.