bug#24149: 25.1; set-transient-map bug

bug#24149: 25.1; set-transient-map bug

[Leo Liu]

1. Enable temp-buffer-browse-mode
2. (cl-loop repeat 2 do (with-output-to-temp-buffer "*test*" (princ "ok")))
3. Check pre-command-hook

#:clear-transient-map will be there forever.

The issue is caused by two identical calls of set-transient-map that
share the same keymap. so deactivation of the second call has an
side-effect on the first call.

Stefan, is the following the right fix?

Thanks,
Leo

diff --git a/lisp/subr.el b/lisp/subr.el
index 2c0be204..b6a38778 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -4542,7 +4542,8 @@ to deactivate this transient map, regardless of KEEP-PRED."
             (with-demoted-errors "set-transient-map PCH: %S"
               (unless (cond
                        ((null keep-pred) nil)
-                       ((not (eq map (cadr overriding-terminal-local-map)))
+                       ((and (keymapp (cadr overriding-terminal-local-map))
+                             (not (eq map (cadr overriding-terminal-local-map))))
                         ;; There's presumably some other transient-map in
                         ;; effect.  Wait for that one to terminate before we
                         ;; remove ourselves.

bug#24149: 25.1; set-transient-map bug

[Stefan Monnier]

> Stefan, is the following the right fix?

Haven't thought enough about it yet, but it looks safe.


        Stefan

bug#24149: 25.1; set-transient-map bug

[Stefan Monnier]

> 1. Enable temp-buffer-browse-mode
> 2. (cl-loop repeat 2 do (with-output-to-temp-buffer "*test*" (princ "ok")))
> 3. Check pre-command-hook
[...]
> Stefan, is the following the right fix?

While the fix is safe, I think it doesn't catch all cases.
A better fix might be something like the untested one below, which makes
sure we only wait when there's still a map of ours.
If it works and looks good to you, please install it.


        Stefan


diff --git a/lisp/subr.el b/lisp/subr.el
index 77bcaa7..4b7cc93 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -4889,7 +4889,8 @@ set-transient-map
             (with-demoted-errors "set-transient-map PCH: %S"
               (unless (cond
                        ((null keep-pred) nil)
-                       ((not (eq map (cadr overriding-terminal-local-map)))
+                       ((and (not (eq map (cadr overriding-terminal-local-map)))
+                             (memq map (cddr overriding-terminal-local-map)))
                         ;; There's presumably some other transient-map in
                         ;; effect.  Wait for that one to terminate before we
                         ;; remove ourselves.

bug#24149: 25.1; set-transient-map bug

[Leo Liu]

On 2016-08-04 09:20 -0400, Stefan Monnier wrote:
> If it works and looks good to you, please install it.

I agree it is a better fix. Pushed commit 84714016 to master.

Thanks,
Leo