>
> Thanks for the reminder; I had seen Zhiwei Chen's message, but not this 
> bug. I'll have a look.
>

This bug is rather strange.  When an input method is used, 
isearch-post-command-hook is executed twice, once in the current isearch 
buffer and once in the minibuffer.

When enable-recursive-minibuffers is unset, the execution of isearch-exit 
fails with "Command attempted to use minibuffer while in minibuffer", so 
the error is not visible (except in *Messages*).

When enable-recursive-minibuffers is set, the execution of isearch-exit 
does not fail, which triggers the current bug.

The immediate fix is attached, but I wonder if the cause is not elswhere, 
that is, if it is indeed intended that isearch-post-command-hook is 
executed in the minibuffer in such a case.