Ignore pending_signals when checking for quits.

pending_signals is often set if no quit is pending.  This results in
bugs in module code if the module returns but no quit is actually
pending.

As a better alternative, add a new process_input environment function
for Emacs 27.  That function processes signals (like maybe_quit).

* configure.ac: Add module snippet for Emacs 27.

* src/module-env-27.h: New file.

* src/emacs-module.h.in: Add process_input function to environment
interface.

* src/emacs-module.c (module_should_quit): Use QUITP macro to check
whether the caller should quit.
(module_process_input): New function.
(initialize_environment): Use it.

* src/eval.c: Remove obsolete comment.

* test/data/emacs-module/mod-test.c (signal_wrong_type_argument)
(signal_errno): New helper functions.
(Fmod_test_sleep_until): New test module function.

* test/src/emacs-module-tests.el (mod-test-sleep-until): New unit
test.

* doc/lispref/internals.texi (Module Misc): Document process_input.

1 files changed, 1 insertions, 4 deletions

diff --git a/src/eval.c b/src/eval.c
index b094fc2e663..b6cdfc911d0 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1575,10 +1575,7 @@ process_quit_flag (void)
    If quit-flag is set to `kill-emacs' the SIGINT handler has received
    a request to exit Emacs when it is safe to do.
 
-   When not quitting, process any pending signals.
-
-   If you change this function, also adapt module_should_quit in
-   emacs-module.c.  */
+   When not quitting, process any pending signals.  */
 
 void
 maybe_quit (void)