* lisp/progmodes/compile.el: Fix bug#36803.

Make sure all mode-lines are updated when compilation-in-progress
is changed since it's visible globally.

(compilation--update-in-progress-mode-line): New function.
(compilation-start, compilation-sentinel): Use it.

1 files changed, 9 insertions, 3 deletions

diff --git a/lisp/progmodes/compile.el b/lisp/progmodes/compile.el
index a7575b5a1a1..39b6134a91d 100644
--- a/lisp/progmodes/compile.el
+++ b/lisp/progmodes/compile.el
@@ -1613,6 +1613,11 @@ If nil, ask to kill it."
   :type 'boolean
   :version "24.3")
 
+(defun compilation--update-in-progress-mode-line ()
+  ;; `compilation-in-progress' affects the mode-line of all
+  ;; buffers when it changes from nil to non-nil or vice-versa.
+  (unless compilation-in-progress (force-mode-line-update t)))
+
 ;;;###autoload
 (defun compilation-start (command &optional mode name-function highlight-regexp)
   "Run compilation command COMMAND (low level interface).
@@ -1806,8 +1811,8 @@ Returns the compilation buffer created."
                   ;; The process may have exited already.
                   (error nil)))
               (run-hook-with-args 'compilation-start-hook proc)
-              (setq compilation-in-progress
-                    (cons proc compilation-in-progress)))
+              (compilation--update-in-progress-mode-line)
+              (push proc compilation-in-progress))
           ;; No asynchronous processes available.
           (message "Executing `%s'..." command)
           ;; Fake mode line display as if `start-process' were run.
@@ -2240,7 +2245,8 @@ commands of Compilation major mode are available.  See
             ;; process is dead, we can delete it now.  Otherwise it
             ;; will stay around until M-x list-processes.
             (delete-process proc)))
-        (setq compilation-in-progress (delq proc compilation-in-progress)))))
+        (setq compilation-in-progress (delq proc compilation-in-progress))
+        (compilation--update-in-progress-mode-line))))
 
 (defun compilation-filter (proc string)
   "Process filter for compilation buffers.