Subject: bug#50125: completion-in-region in shell.el

From: Madhu <[email-masked]>
Date: Thu, 19 Aug 2021 21:22:06 +0530

In a *shell* buffer, if I position the cursor after typing "pass"
and invoke M-: (shell-dynamic-completion-command),

this should yield a completion "passwd" if /bin is in exec-path.
However it errors out with

error: (wrong-number-of-arguments (3 . 4) 5)
  completion-in-region(484 486 #f(compiled-function (string pred action) #<bytecode -0x6e453bfcd314ab>) :exit-function #f(compiled-function (string finished) #<bytecode -0x9a98b1a3de78800>))
  apply(completion-in-region (484 486 #f(compiled-function (string pred action) #<bytecode -0x6e453bfcd314ab>) :exit-function #f(compiled-function (string finished) #<bytecode -0x9a98b1a3de78800>)))
  shell-dynamic-complete-command()
  eval((shell-dynamic-complete-command) t)
  eval-expression((shell-dynamic-complete-command) nil nil 127)
  funcall-interactively(eval-expression (shell-dynamic-complete-command) nil nil 127)
  call-interactively(eval-expression nil nil)
  command-execute(eval-expression)

The completion data functions shell-environment-variable-completion and
shell-command-completion include an :exit-function keyword value pair in
the result. But this cannot be passed on to completion-in-region.  (How
is this exit-function to be used at all?)

Commit e71564921ec760638105c910fdfae8b648724130 fixed similar issues in
comint.el, and probably missed shell.el during that pass

* lisp/shell.el (shell-dynamic-complete-command)
(shell-dynamic-complete-environment-variable): Correctly call
completion-in-region.

>From 913b77f13b5d2a7cb3e91d0c057ea3321740f845 Mon Sep 17 00:00:00 2001
From: Madhu <[email-masked]>
Date: Thu, 19 Aug 2021 20:57:48 +0530
Subject: [PATCH] * lisp/shell.el (shell-dynamic-complete-command)
 (shell-dynamic-complete-environment-variable): Correctly call
 completion-in-region.

---
 lisp/shell.el | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lisp/shell.el b/lisp/shell.el
index 292f267d2e..5cdc0385a6 100644
--- a/lisp/shell.el
+++ b/lisp/shell.el
@@ -1199,7 +1199,7 @@ shell-dynamic-complete-command
     (if data
 	(prog2 (unless (window-minibuffer-p)
 		 (message "Completing command name..."))
-	    (apply #'completion-in-region data)))))
+            (completion-in-region (nth 0 data) (nth 1 data) (nth 2 data))))))
 
 (defun shell-command-completion ()
   "Return the completion data for the command at point, if any."
@@ -1314,7 +1314,7 @@ shell-dynamic-complete-environment-variable
     (if data
 	(prog2 (unless (window-minibuffer-p)
 		 (message "Completing variable name..."))
-	    (apply #'completion-in-region data)))))
+	    (completion-in-region (nth 0 data) (nth 1 data) (nth 2 data))))))

 (defun shell-environment-variable-completion ()
-- 
2.31.0