bug#17239: 24.3.50; competion error (cl-assertion-failed (string-prefix-p uprefix ustring))

[Nicolas Richard]

Hello,

Recipe:
$ emacs -Q
C-x C-f
/ C-b TAB ;; hit tab between the last two slashes.
=> error.

Debugger entered--Lisp error: (cl-assertion-failed (string-prefix-p uprefix 
ustring))
  signal(cl-assertion-failed ((string-prefix-p uprefix ustring)))
  completion--file-name-table("~/sources/running-emacs//" 24 
completion--unquote)
  complete-with-action(completion--unquote completion--file-name-table 
"~/sources/running-emacs//" 24)
  #[257 "\303\302\300\301$\207" ["~/sources/running-emacs//" 24 
completion--unquote complete-with-action] 6 "\n\n(fn 
TABLE)"](completion--file-name-table)
  #[0 "\302\300\301\242\301\211\242A\240\210\242!\240\207" [#[257 
"\303\302\300\301$\207" ["~/sources/running-emacs//" 24 completion--unquote 
complete-with-action] 6 "\n\n(fn TABLE)"] (nil) (nil)] 5 "\n\n(fn)"]()
  funcall(#[0 "\302\300\301\242\301\211\242A\240\210\242!\240\207" [#[257 
"\303\302\300\301$\207" ["~/sources/running-emacs//" 24 completion--unquote 
complete-with-action] 6 "\n\n(fn TABLE)"] (nil) (nil)] 5 "\n\n(fn)"])
  completion--some(#[257 "\303\302\300\301$\207" ["~/sources/running-emacs//" 
24 completion--unquote complete-with-action] 6 "\n\n(fn TABLE)"] 
(completion--embedded-envvar-table completion--file-name-table))
  read-file-name-internal("~/sources/running-emacs//" 24 completion--unquote)
  completion--nth-completion(1 "~/sources/running-emacs//" 
read-file-name-internal file-exists-p 24 (metadata (category . file) 
(completion--unquote-requote . t)))
  completion-try-completion("~/sources/running-emacs//" read-file-name-internal 
file-exists-p 24 (metadata (category . file) (completion--unquote-requote . t)))
  completion--do-completion(12 37)
  completion--in-region-1(12 37)
  #[1028 "
\n\203!\304!\203\202\305!\305\306\"F\307\310!\210\311\"*\207" 
[minibuffer-completion-predicate minibuffer-completion-table 
completion-in-region-mode-predicate completion-in-region--data markerp 
copy-marker t completion-in-region-mode 1 completion--in-region-1] 8 "\n\n(fn 
START END COLLECTION PREDICATE)"](12 37 read-file-name-internal file-exists-p)
  apply(#[1028 
"
\n\203!\304!\203\202\305!\305\306\"F\307\310!\210\311\"*\207" 
[minibuffer-completion-predicate minibuffer-completion-table 
completion-in-region-mode-predicate completion-in-region--data markerp 
copy-marker t completion-in-region-mode 1 completion--in-region-1] 8 "\n\n(fn 
START END COLLECTION PREDICATE)"] (12 37 read-file-name-internal file-exists-p))
  #[771 
":\2030@\301=\203\300\242\302A\"\303#\207\304@\305\306\307\310\311\312\300!\313\"\314\315%A##\207\304\316\"\207"
 [(#0) t append nil apply apply-partially make-byte-code 642 "\300\242#\207" 
vconcat vector [] 7 "\n\n(fn FUNS GLOBAL &rest ARGS)" #[1028 
"
\n\203!\304!\203\202\305!\305\306\"F\307\310!\210\311\"*\207" 
[minibuffer-completion-predicate minibuffer-completion-table 
completion-in-region-mode-predicate completion-in-region--data markerp 
copy-marker t completion-in-region-mode 1 completion--in-region-1] 8 "\n\n(fn 
START END COLLECTION PREDICATE)"]] 12 "\n\n(fn FUNS GLOBAL ARGS)"](nil nil (12 
37 read-file-name-internal file-exists-p))
  completion--in-region(12 37 read-file-name-internal file-exists-p)
  completion-in-region(12 37 read-file-name-internal file-exists-p)
  minibuffer-complete()
  call-interactively(minibuffer-complete nil nil)
  command-execute(minibuffer-complete)
  read-from-minibuffer("Find file: " "~/sources/running-emacs/" (keymap (keymap 
(32)) keymap (10 . minibuffer-complete-and-exit) (13 . 
minibuffer-complete-and-exit) keymap (menu-bar keymap (minibuf "Minibuf" keymap 
(tab menu-item "Complete" minibuffer-complete :help "Complete as far as 
possible") (space menu-item "Complete Word" minibuffer-complete-word :help 
"Complete at most one word") (63 menu-item "List Completions" 
minibuffer-completion-help :help "Display all possible completions") 
"Minibuf")) (27 keymap (118 . switch-to-completions)) (prior . 
switch-to-completions) (63 . minibuffer-completion-help) (32 . 
minibuffer-complete-word) (9 . minibuffer-complete) keymap (menu-bar keymap 
(minibuf "Minibuf" keymap (previous menu-item "Previous History Item" 
previous-history-element :help "Put previous minibuffer history element in the 
minibuffer") (next menu-item "Next History Item" next-history-element :help 
"Put next minibuffer history element in the minibuffer") (isearch-backward 
menu-item "Isearch History Backward" isearch-backward :help "Incrementally 
search minibuffer history backward") (isearch-forward menu-item "Isearch 
History Forward" isearch-forward :help "Incrementally search minibuffer history 
forward") (return menu-item "Enter" exit-minibuffer :key-sequence "" :help 
"Terminate input and exit minibuffer") (quit menu-item "Quit" 
abort-recursive-edit :help "Abort input and exit minibuffer") "Minibuf")) (10 . 
exit-minibuffer) (13 . exit-minibuffer) (7 . abort-recursive-edit) (C-tab . 
file-cache-minibuffer-complete) (9 . self-insert-command) (XF86Back . 
previous-history-element) (up . previous-history-element) (prior . 
previous-history-element) (XF86Forward . next-history-element) (down . 
next-history-element) (next . next-history-element) (27 keymap (114 . 
previous-matching-history-element) (115 . next-matching-history-element) (112 . 
previous-history-element) (110 . next-history-element))) nil file-name-history 
"~/sources/running-emacs/" nil)
  completing-read-default("Find file: " read-file-name-internal file-exists-p 
confirm-after-completion "~/sources/running-emacs/" file-name-history 
"~/sources/running-emacs/" nil)
  completing-read("Find file: " read-file-name-internal file-exists-p 
confirm-after-completion "~/sources/running-emacs/" file-name-history 
"~/sources/running-emacs/")
  read-file-name-default("Find file: " nil "~/sources/running-emacs/" 
confirm-after-completion nil nil)
  read-file-name("Find file: " nil "~/sources/running-emacs/" 
confirm-after-completion)
  find-file-read-args("Find file: " confirm-after-completion)
  byte-code("\300\301\302 \"\207" [find-file-read-args "Find file: " 
confirm-nonexistent-file-or-buffer] 3)
  call-interactively(find-file nil nil)
  command-execute(find-file)


In GNU Emacs 24.3.50.10 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2014-04-07 on geodiff-mac3

-- 
Nico.