bug#12704: 24.2.50; QuitError during redisplay: (eval (\` ((-3 (\, (propertize "%p" ...

[Drew Adams]

> So if the msg resulted from my hitting C-g then the fact that 
> the message is present indicates that something must have changed 
> `inhibit-quit' to nil.
...
> I don't see anywhere that `inhibit-quit' could be bound to 
> nil in that code.  But I didn't recursively check the def
> of each function that is called by `count-lines'.

FYI, I think I found the culprit.  In my file icomplete+.el I redefine some
functions from icomplete.el.  I include macro `while-no-input' in the file so
that the file can be byte-compiled in Emacs versions prior to Emacs 23 and the
byte-compiled file used with Emacs 23.  I include macro `with-local-quit' too,
because it is used by `while-no-input'.  And macro `with-local-quit' binds
`inhibit-quit' to nil.

So most likely I hit C-g while the mode line was being redisplayed, which caused
the redisplay code to print that error msg to *Messages*.

It happened again today, when I was trying to use the debugger with icomplete
code.

Error during redisplay: (eval (mode-line-eol-desc)) signaled (quit)



[BTW, I also got this unrelated internal error when trying to test some related
code:
Error in post-command-hook ((lambda nil (let ((non-essential t)) (run-hooks
(quote icomplete-post-command-hook))))): (error "Internal error: *scratch*
doesn't match \\`mcs")]