Re: [Bug: 21.5-b21] trapping problems with call-process-done

On Tue, Sep 20, 2005 at 10:51:14AM +0200, clemens(a)ghanima.endorphin.org wrote: (Summary of my old mail: This error occurs because the following sketch (catch 'call-process-done (while t (run-something-via-the-pre-idle-hook-that-throws-call-process-done))) does not work, because there is no way to throw something from the code that is executed as caller from the pre-idle-hook.) Here is a litte update on that bug. I presumed incorrectly that the (with-trapping-errors ..) macro was catching 'call-process-done. In fact, the tag that actually catches this throw is pushed on the catchlist by safe_run_hook_trapping_problems which is called before font-lock-pre-idle-hook in event-stream.c. safe_run_hook_trapping_problems comes from eval.c. This function per default catches errors and signals. Calling it with NO_INHIBIT_THROWS active in the flags parameter enables the process sentinel to throws its call-process-done symbol out of this safe_run_hook.._problems unwind prison. Setting this flag cures my problem insofar, that I don't have to C-g twice to get out of the loop installed by call-process-internal (process.el:284), that would normally be terminated by catching call-process-done. However, the question is: Is safe_run_hook_trappings supposed to throw things and interrupt the execution of its callers on the stack frame? In this case the execution of run_pre_idle_hook <- redisplay <- status_notify <- delete-process. (callee <- caller) At least at delete-process, I spot a potential problem (process.c:2180) because in this method status_notify is called before remove_proces(process) which - I presume - is for housekeeping. A never-returning status_notify would prevent this housekeeping. This can be fixed easily, if that's what we want. Unfortunately, I lack the insight to decide whether this is correct or not. Please comment on this issue, as I'm not sure how to proceed. Best Regards, -- Fruhwirth Clemens - http://clemens.endorphin.org for robots: sp4mtrap(a)endorphin.org