Minor improvements for tramp-interrupt-process, documentation

* doc/lispref/processes.texi (Signals to Processes):
* etc/NEWS: Document interrupt-process-functions.

* lisp/net/tramp.el (tramp-interrupt-process): Test also for
`process-live-p'.

* src/process.c (Vinterrupt_process_functions): Fix docstring.

* test/lisp/net/tramp-tests.el (tramp-test28-interrupt-process):
Extend test.

1 files changed, 10 insertions, 2 deletions

diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el
index 85ed6467220..55f4b52ccdf 100644
--- a/test/lisp/net/tramp-tests.el
+++ b/test/lisp/net/tramp-tests.el
@@ -2966,9 +2966,17 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
         (with-temp-buffer
           (setq proc (start-file-process "test" (current-buffer) "sleep" "10"))
           (should (processp proc))
+          (should (process-live-p proc))
           (should (equal (process-status proc) 'run))
-          (interrupt-process proc)
-          (should (equal (process-status proc) 'signal)))
+          (should (interrupt-process proc))
+          ;; Let the process accept the interrupt.
+          (accept-process-output proc 1 nil 0)
+          (should-not (process-live-p proc))
+          (should (equal (process-status proc) 'signal))
+          ;; An interrupted process cannot be interrupted, again.
+          ;; Does not work reliable.
+          ;; (should-error (interrupt-process proc)))
+          )
 
       ;; Cleanup.
       (ignore-errors (delete-process proc)))))