bug#64516: [PATCH] docview: Only enable imenu when supported

[Morgan Smith]

Hello,

First of all I'd like to apologize for dragging this out and missing
some details.  If I paid a little more attention this would likely be
done by now :P

Tassilo Horn <tsdh@gnu.org> writes:

> Why do you ignore the error altogether?

So we have 3 scenarios: mutool not installed, mutool failed, and mutool
is successful.

Your patch would send a message on setup when mutool fails, but would
not say anything in the other two scenarios.

My patch would be silent on setup.

Both patches would give the user an error if they actually try to use
imenu.

In my opinion, we should either be completely silent (on setup) or send a 
message
when imenu is set up correctly.  If you wanted to send a message when it
fails I would accept that, but maybe we should consider also sending the
message when mutool is not installed.


Also, we have a macro 'with-demoted-errors' but we are missing a
'with-demoted-error' macro that lets you specify what error to demote.
It would be cool if you converted this part of your patch into a
definition of a 'with-demoted-error' macro.


--8<---------------cut here---------------start------------->8---
+    (condition-case imenu-error
+        (doc-view-imenu-setup)
+      (imenu-unavailable (message "imenu support unavailable: %s"
+                                  (cadr imenu-error))))
--8<---------------cut here---------------end--------------->8---