[elpa] externals/transient ef921d3048 258/366: transient--post-command: Deal with mystery quits

[Jonas Bernoulli]

branch: externals/transient
commit ef921d304871ab3ab029b8ddc8bdfa1173143a84
Author: Jonas Bernoulli <jonas@bernoul.li>
Commit: Jonas Bernoulli <jonas@bernoul.li>

    transient--post-command: Deal with mystery quits
    
    Sometimes when `post-command-hook' is run, then `this-command' and
    `this-original-command' are nil and `pre-command-hook' was not run.
    This appears to be due to something(tm) setting `quit-flag' to t.
    
    One such situation that I could semi-reliably reproduce is entering
    some transient prefix and then immediately quitting with `C-g'.  For
    some (but not all) prefixes, that would often (but not always) bypass
    `pre-command-hook', fail to invoke `transient-quit-one', and go
    straight to the `post-command-hook' (but only the first time around
    and not after invoking some other suffix first).
    
    Here is such a failed invocation using (setq transient--debug t):
    
    ,----
    | -- setup            (cmd: notmuch-search-stash-transient, event: "c", 
exit: nil)
    | -- stack-zap        (cmd: notmuch-search-stash-transient, event: "c", 
exit: nil)
    | -- init-transient   (cmd: notmuch-search-stash-transient, event: "c", 
exit: nil)
    |    push transient--transient-map
    |    push transient--redisplay-map
    | -- post-command     (cmd: notmuch-search-stash-transient, event: "c", 
exit: nil)
    |    pop  transient--redisplay-map
    |    push transient--redisplay-map
    | Quit
    | -- post-command     (cmd: (nil nil notmuch-search-stash-transient), 
event: "", exit: nil)
    | Error during redisplay: (mode-line-default-help-echo #<window 3 on ...) 
signaled (quit)
    `----
    
    It should look like this instead:
    
    ,----
    | -- setup            (cmd: notmuch-search-stash-transient, event: "c", 
exit: nil)
    | -- stack-zap        (cmd: notmuch-search-stash-transient, event: "c", 
exit: nil)
    | -- init-transient   (cmd: notmuch-search-stash-transient, event: "c", 
exit: nil)
    |    push transient--transient-map
    |    push transient--redisplay-map
    | -- post-command     (cmd: notmuch-search-stash-transient, event: "c", 
exit: nil)
    |    pop  transient--redisplay-map
    |    push transient--redisplay-map
    | -- pre-command      (cmd: transient-quit-one, event: "C-g", exit: nil)
    | -- pre-exit         (cmd: transient-quit-one, event: "C-g", exit: t)
    |    pop  transient--transient-map
    |    pop  transient--redisplay-map
    | -- post-command     (cmd: transient-quit-one, event: "C-g", exit: t)
    `----
    
    For now at least deal with `this-command' being nil by taking extra
    steps to allow quitting the transient.  This might not always be the
    right thing to do but in the one case that I could reproduce, it is.
    Show message "Quit transient!" in the hope that this will make it into
    bug-reports, if appropriate, while still being silent enough to not be
    a bother when quitting was actually the right thing to do.
---
 lisp/transient.el | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lisp/transient.el b/lisp/transient.el
index e4026d8a4a..50a8109562 100644
--- a/lisp/transient.el
+++ b/lisp/transient.el
@@ -1973,6 +1973,11 @@ value.  Otherwise return CHILDREN as is."
 
 (defun transient--post-command ()
   (transient--debug 'post-command)
+  (unless this-command
+    (transient--debug "-- force pre-exit from post-command")
+    (message "Quit transient!")
+    (transient--pre-exit)
+    (setq transient--exitp t))
   (if transient--exitp
       (progn
         (unless (and (eq transient--exitp 'replace)
@@ -2048,7 +2053,8 @@ value.  Otherwise return CHILDREN as is."
     (if (symbolp arg)
         (message "-- %-16s (cmd: %s, event: %S, exit: %s)"
                  arg
-                 (transient--suffix-symbol this-command)
+                 (or (transient--suffix-symbol this-command)
+                     (list this-command this-original-command last-command))
                  (key-description (this-command-keys-vector))
                  transient--exitp)
       (apply #'message arg args))))