MI return error changed from 6.3 to 6.4?

[Dirk Behme <dirk.behme@googlemail.com>]

Hello,

after upgrade from GDB 6.3 to 6.4 I noticed that the error 
return behavior of MI interface invoked by 
"--interpreter=mi" changed. While with 6.3 an "^error" was 
returned which can be used by programs to react, 6.4 only 
returns "^done":

GDB 6.3:

(gdb)
ererwrererwrewr
&"ererwrererwrewr\n"
&"Undefined command: \"ererwrererwrewr\".  Try \"help\".\n"
^error,msg="Undefined command: \"ererwrererwrewr\".  Try 
\"help\"."
(gdb)

GDB 6.4:

(gdb)
srwwerrweweer
&"srwwerrweweer\n"
&"Undefined command: \"srwwerrweweer\".  Try \"help\".\n"
^done
(gdb)

With this, a GUI interface has the problem that it can't 
decide if the GDB
has some problems parsing the command given to it or not 
because it scans for
the "^error" string as result. With 6.4 this doesn't work 
any more.

Do I miss anything here? What is the new recommended way to 
do this job?

Sorry if this is a FAQ, but searching release note and list 
archives I can't find a hint for this.

Thanks

Dirk