Subject: 25.0.92; Having pcomplete-ignore-case different from completion-ignore-case can lead to an error

From: Dmitry Gutov <[email-masked]>
Date: Sat, 26 Mar 2016 02:21:51 +0200

1. (setq pcomplete-ignore-case t)
2. Keep completion-ignore-case at its default nil value.
3. M-x shell
3. Type 'cd /Usr/', press C-M-i.
4. See the below error.

Should the former variable just be made into an alias for the latter one?

Debugger entered--Lisp error: (error "Internal error: usr/games/ doesn’t match \\`Usr\\(.*?\\)/")
  signal(error ("Internal error: usr/games/ doesn’t match \\`Usr\\(.*?\\)/"))
  error("Internal error: %s doesn't match %s" "usr/games/" "\\`Usr\\(.*?\\)/")
  completion-pcm--merge-completions(("usr/games/" "usr/./" "usr/lib/" "usr/local/" "usr/../" "usr/bin/" "usr/share/" "usr/X11R6/" "usr/src/" "usr/locale/" "usr/include/" "usr/lib32/" "usr/sbin/") (#("Usr" 0 3 (fontified t)) any "/"))
  completion-pcm--merge-try((#("Usr" 0 3 (fontified t)) any "/") ("usr/games/" "usr/./" "usr/lib/" "usr/local/" "usr/../" "usr/bin/" "usr/share/" "usr/X11R6/" "usr/src/" "usr/locale/" "usr/include/" "usr/lib32/" "usr/sbin/") #("/" 0 1 (fontified t)) "")
  #[257 "\300.
  completion--some(#[257 "\300.
  completion--do-completion(#<marker at 26 in *shell*> 31)
  completion--in-region-1(#<marker at 26 in *shell*> 31)
  completion-at-point()
  complete-symbol(nil)
  funcall-interactively(complete-symbol nil)
  call-interactively(complete-symbol nil nil)
  command-execute(complete-symbol)

In GNU Emacs 25.0.92.4 (x86_64-unknown-linux-gnu, GTK+ Version 3.16.7)
 of 2016-03-20 built on axl
Repository revision: 26f9c5075ff273013418a66b70fae477301d41d5
Windowing system distributor 'The X.Org Foundation', version 11.0.11702000
System Description:	Ubuntu 15.10