Implement `interrupt-process-functions'

* lisp/net/tramp.el (tramp-interrupt-process): Rename from
`tramp-advice-interrupt-process'.  Adapt according to changed API.
(top): Add it to `interrupt-process-functions'.

* src/process.c (Finternal_default_interrupt_process): New defun.
(Finterrupt_process): Change implementation, based on
Vinterrupt_process_functions.
(Vinterrupt_process_functions): New defvar.

* test/lisp/net/tramp-tests.el (tramp-test40-unload): Do not
test removal of advice.

1 files changed, 30 insertions, 3 deletions

diff --git a/src/process.c b/src/process.c
index 19009515336..e7ee99ab3d9 100644
--- a/src/process.c
+++ b/src/process.c
@@ -6677,6 +6677,18 @@ process_send_signal (Lisp_Object process, int signo, Lisp_Object current_group,
   unblock_child_signal (&oldset);
 }
 
+DEFUN ("internal-default-interrupt-process",
+       Finternal_default_interrupt_process,
+       Sinternal_default_interrupt_process, 0, 2, 0,
+       doc: /* Default function to interrupt process PROCESS.
+It shall be the last element in list `interrupt-process-functions'.
+See function `interrupt-process' for more details on usage.  */)
+  (Lisp_Object process, Lisp_Object current_group)
+{
+  process_send_signal (process, SIGINT, current_group, 0);
+  return process;
+}
+
 DEFUN ("interrupt-process", Finterrupt_process, Sinterrupt_process, 0, 2, 0,
        doc: /* Interrupt process PROCESS.
 PROCESS may be a process, a buffer, or the name of a process or buffer.
@@ -6688,11 +6700,14 @@ If the process is a shell, this means interrupt current subjob
 rather than the shell.
 
 If CURRENT-GROUP is `lambda', and if the shell owns the terminal,
-don't send the signal.  */)
+don't send the signal.
+
+This function calls the functions of `interrupt-process-functions' in
+the order of the list, until one of them returns non-`nil'.  */)
   (Lisp_Object process, Lisp_Object current_group)
 {
-  process_send_signal (process, SIGINT, current_group, 0);
-  return process;
+  return CALLN (Frun_hook_with_args_until_success, Qinterrupt_process_functions,
+                process, current_group);
 }
 
 DEFUN ("kill-process", Fkill_process, Skill_process, 0, 2, 0,
@@ -8176,6 +8191,17 @@ non-nil value means that the delay is not reset on write.
 The variable takes effect when `start-process' is called.  */);
   Vprocess_adaptive_read_buffering = Qt;
 
+  DEFVAR_LISP ("interrupt-process-functions", Vinterrupt_process_functions,
+               doc: /* List of functions to be called for `interrupt-function'.
+The arguments of the functions are the same as for `interrupt-function'.
+These functions are called in the order of the list, until one of them
+returns non-`nil'.  */);
+  Vinterrupt_process_functions = list1 (Qinternal_default_interrupt_process);
+
+  DEFSYM (Qinternal_default_interrupt_process,
+          "internal-default-interrupt-process");
+  DEFSYM (Qinterrupt_process_functions, "interrupt-process-functions");
+
   defsubr (&Sprocessp);
   defsubr (&Sget_process);
   defsubr (&Sdelete_process);
@@ -8218,6 +8244,7 @@ The variable takes effect when `start-process' is called.  */);
   defsubr (&Saccept_process_output);
   defsubr (&Sprocess_send_region);
   defsubr (&Sprocess_send_string);
+  defsubr (&Sinternal_default_interrupt_process);
   defsubr (&Sinterrupt_process);
   defsubr (&Skill_process);
   defsubr (&Squit_process);