Fix Bug#22557

* lisp/filenotify.el (file-notify-callback): Do not send a
`stopped' event in case of backup by renaming.  (Bug#22557)

* test/automated/Makefile.in: Use $(SELECTOR_EXPENSIVE) for
all targets but check and check-maybe.

* test/automated/file-notify-tests.el
(file-notify--test-read-event-timeout): New defconst.
(file-notify--deftest-remote, file-notify--wait-for-events)
(file-notify-test02-events)
(file-notify-test04-file-validity)
(file-notify-test06-many-events): Use it.
(file-notify--test-cleanup): Make it more robust.  Delete also
backup file.
(file-notify-test07-backup): New test.

3 files changed, 116 insertions, 36 deletions

diff --git a/lisp/filenotify.el b/lisp/filenotify.el
index faa801ee6e7..66e7fd7a315 100644
--- a/lisp/filenotify.el
+++ b/lisp/filenotify.el
@@ -242,10 +242,14 @@ EVENT is the cadr of the event in `file-notify-handle-event'
           (and
            (memq action '(deleted renamed))
            (= (length (cdr registered)) 1)
+           ;; Not, when a file is backed up.
+           (not (and (stringp file1) (backup-file-name-p file1)))
            (or
+            ;; Watched file or directory is concerned.
             (string-equal
              (file-name-nondirectory file)
              (file-name-nondirectory (car registered)))
+            ;; File inside a watched directory is concerned.
             (string-equal
              (file-name-nondirectory file)
              (car (cadr registered)))))))
diff --git a/test/automated/Makefile.in b/test/automated/Makefile.in
index 2534a65a9a3..5074d515499 100644
--- a/test/automated/Makefile.in
+++ b/test/automated/Makefile.in
@@ -89,10 +89,14 @@ WRITE_LOG = > $@ 2>&1 || { stat=ERROR; cat $@; }; echo $$stat: $@
 ## Beware: it approximates 'no-byte-compile', so watch out for false-positives!
 SELECTOR_DEFAULT = (quote (not (tag :expensive-test)))
 SELECTOR_EXPENSIVE = nil
-ifndef SELECTOR
+ifdef SELECTOR
+SELECTOR_ACTUAL=$(SELECTOR)
+else ifeq ($(MAKECMDGOALS),check)
+SELECTOR_ACTUAL=$(SELECTOR_DEFAULT)
+else ifeq ($(MAKECMDGOALS),check-maybe)
 SELECTOR_ACTUAL=$(SELECTOR_DEFAULT)
 else
-SELECTOR_ACTUAL=$(SELECTOR)
+SELECTOR_ACTUAL=$(SELECTOR_EXPENSIVE)
 endif
 
 
diff --git a/test/automated/file-notify-tests.el b/test/automated/file-notify-tests.el
index 5fc4ff8bf42..4261507f59f 100644
--- a/test/automated/file-notify-tests.el
+++ b/test/automated/file-notify-tests.el
@@ -62,6 +62,10 @@
 (defvar file-notify--test-event nil)
 (defvar file-notify--test-events nil)
 
+(defconst file-notify--test-read-event-timeout 0.02
+  "Timeout for `read-event' calls.
+It is different for local and remote file notification libraries.")
+
 (defun file-notify--test-timeout ()
   "Timeout to wait for arriving events, in seconds."
   (cond
@@ -74,19 +78,20 @@
   "Cleanup after a test."
   (file-notify-rm-watch file-notify--test-desc)
 
-  (when (and file-notify--test-tmpfile
-             (file-exists-p file-notify--test-tmpfile))
+  (ignore-errors
+    (delete-file (file-newest-backup file-notify--test-tmpfile)))
+  (ignore-errors
     (if (file-directory-p file-notify--test-tmpfile)
         (delete-directory file-notify--test-tmpfile 'recursive)
       (delete-file file-notify--test-tmpfile)))
-  (when (and file-notify--test-tmpfile1
-             (file-exists-p file-notify--test-tmpfile1))
+  (ignore-errors
     (if (file-directory-p file-notify--test-tmpfile1)
         (delete-directory file-notify--test-tmpfile1 'recursive)
       (delete-file file-notify--test-tmpfile1)))
-  (when (file-remote-p temporary-file-directory)
-    (tramp-cleanup-connection
-     (tramp-dissect-file-name temporary-file-directory) nil 'keep-password))
+  (ignore-errors
+    (when (file-remote-p temporary-file-directory)
+      (tramp-cleanup-connection
+       (tramp-dissect-file-name temporary-file-directory) nil 'keep-password)))
 
   (setq file-notify--test-tmpfile nil
         file-notify--test-tmpfile1 nil
@@ -155,6 +160,7 @@ remote host, or nil."
      :tags '(:expensive-test)
      (let* ((temporary-file-directory
              file-notify-test-remote-temporary-file-directory)
+            (file-notify--test-read-event-timeout 0.1)
             (ert-test (ert-get-test ',test)))
        (skip-unless (file-notify--test-remote-enabled))
        (tramp-cleanup-connection
@@ -285,7 +291,7 @@ and the event to `file-notify--test-events'."
 TIMEOUT is the maximum time to wait for, in seconds."
   `(with-timeout (,timeout (ignore))
      (while (null ,until)
-       (read-event nil nil 0.1))))
+       (read-event nil nil file-notify--test-read-event-timeout))))
 
 (defmacro file-notify--test-with-events (events &rest body)
   "Run BODY collecting events and then compare with EVENTS.
@@ -342,7 +348,7 @@ longer than timeout seconds for the events to be delivered."
                (t '(created changed deleted stopped)))
             (write-region
              "another text" nil file-notify--test-tmpfile nil 'no-message)
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (delete-file file-notify--test-tmpfile))
           ;; `file-notify-rm-watch' fires the `stopped' event.  Suppress it.
           (let (file-notify--test-events)
@@ -371,10 +377,10 @@ longer than timeout seconds for the events to be delivered."
               '((changed deleted stopped)
                 (changed changed deleted stopped)))
              (t '(changed changed deleted stopped)))
-          (read-event nil nil 0.1)
+          (read-event nil nil file-notify--test-read-event-timeout)
           (write-region
            "another text" nil file-notify--test-tmpfile nil 'no-message)
-          (read-event nil nil 0.1)
+          (read-event nil nil file-notify--test-read-event-timeout)
           (delete-file file-notify--test-tmpfile))
         ;; `file-notify-rm-watch' fires the `stopped' event.  Suppress it.
         (let (file-notify--test-events)
@@ -405,10 +411,10 @@ longer than timeout seconds for the events to be delivered."
                ((string-equal (file-notify--test-library) "kqueue")
                 '(created changed deleted stopped))
                (t '(created changed deleted deleted stopped)))
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (write-region
              "any text" nil file-notify--test-tmpfile nil 'no-message)
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (delete-directory temporary-file-directory 'recursive))
           ;; `file-notify-rm-watch' fires the `stopped' event.  Suppress it.
           (let (file-notify--test-events)
@@ -440,17 +446,17 @@ longer than timeout seconds for the events to be delivered."
                 '(created changed created changed deleted stopped))
                (t '(created changed created changed
                     deleted deleted deleted stopped)))
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (write-region
              "any text" nil file-notify--test-tmpfile nil 'no-message)
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (copy-file file-notify--test-tmpfile file-notify--test-tmpfile1)
             ;; The next two events shall not be visible.
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (set-file-modes file-notify--test-tmpfile 000)
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (set-file-times file-notify--test-tmpfile '(0 0))
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (delete-directory temporary-file-directory 'recursive))
           ;; `file-notify-rm-watch' fires the `stopped' event.  Suppress it.
           (let (file-notify--test-events)
@@ -480,13 +486,13 @@ longer than timeout seconds for the events to be delivered."
                ((string-equal (file-notify--test-library) "kqueue")
                 '(created changed renamed deleted stopped))
                (t '(created changed renamed deleted deleted stopped)))
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (write-region
              "any text" nil file-notify--test-tmpfile nil 'no-message)
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (rename-file file-notify--test-tmpfile file-notify--test-tmpfile1)
             ;; After the rename, we won't get events anymore.
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (delete-directory temporary-file-directory 'recursive))
           ;; `file-notify-rm-watch' fires the `stopped' event.  Suppress it.
           (let (file-notify--test-events)
@@ -514,14 +520,14 @@ longer than timeout seconds for the events to be delivered."
                     (file-remote-p temporary-file-directory))
                 '(attribute-changed attribute-changed attribute-changed))
                (t '(attribute-changed attribute-changed)))
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (write-region
              "any text" nil file-notify--test-tmpfile nil 'no-message)
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (set-file-modes file-notify--test-tmpfile 000)
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (set-file-times file-notify--test-tmpfile '(0 0))
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (delete-file file-notify--test-tmpfile))
           ;; `file-notify-rm-watch' fires the `stopped' event.  Suppress it.
           (let (file-notify--test-events)
@@ -678,10 +684,10 @@ longer than timeout seconds for the events to be delivered."
                 (changed changed deleted stopped)))
              (t '(changed changed deleted stopped)))
           (should (file-notify-valid-p file-notify--test-desc))
-          (read-event nil nil 0.1)
+          (read-event nil nil file-notify--test-read-event-timeout)
           (write-region
            "another text" nil file-notify--test-tmpfile nil 'no-message)
-          (read-event nil nil 0.1)
+          (read-event nil nil file-notify--test-read-event-timeout)
           (delete-file file-notify--test-tmpfile))
         ;; After deleting the file, the descriptor is not valid anymore.
         (should-not (file-notify-valid-p file-notify--test-desc))
@@ -713,10 +719,10 @@ longer than timeout seconds for the events to be delivered."
                 '(created changed deleted stopped))
                (t '(created changed deleted deleted stopped)))
             (should (file-notify-valid-p file-notify--test-desc))
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (write-region
              "any text" nil file-notify--test-tmpfile nil 'no-message)
-            (read-event nil nil 0.1)
+            (read-event nil nil file-notify--test-read-event-timeout)
             (delete-directory temporary-file-directory t))
           ;; After deleting the parent directory, the descriptor must
           ;; not be valid anymore.
@@ -814,9 +820,9 @@ longer than timeout seconds for the events to be delivered."
           (let ((source-file-list source-file-list)
                 (target-file-list target-file-list))
             (while (and source-file-list target-file-list)
-              (read-event nil nil 0.1)
+              (read-event nil nil file-notify--test-read-event-timeout)
               (write-region "" nil (pop source-file-list) nil 'no-message)
-              (read-event nil nil 0.1)
+              (read-event nil nil file-notify--test-read-event-timeout)
               (write-region "" nil (pop target-file-list) nil 'no-message))))
         (file-notify--test-with-events
             (cond
@@ -829,16 +835,82 @@ longer than timeout seconds for the events to be delivered."
           (let ((source-file-list source-file-list)
                 (target-file-list target-file-list))
             (while (and source-file-list target-file-list)
-              (rename-file (pop source-file-list) (pop target-file-list) t)
-              (read-event nil nil 0.02))))
+              (read-event nil nil file-notify--test-read-event-timeout)
+              (rename-file (pop source-file-list) (pop target-file-list) t))))
         (file-notify--test-with-events (make-list n 'deleted)
           (dolist (file target-file-list)
-            (prog1 (delete-file file) (read-event nil nil 0.02)))))
+            (read-event nil nil file-notify--test-read-event-timeout)
+            (delete-file file) file-notify--test-read-event-timeout)))
+
+    ;; Cleanup.
     (file-notify--test-cleanup)))
 
 (file-notify--deftest-remote file-notify-test06-many-events
    "Check that events are not dropped for remote directories.")
 
+(ert-deftest file-notify-test07-backup ()
+  "Check that backup keeps file supervision."
+  (skip-unless (file-notify--test-local-enabled))
+
+  (unwind-protect
+      (progn
+        (setq file-notify--test-tmpfile (file-notify--test-make-temp-name))
+        (write-region "any text" nil file-notify--test-tmpfile nil 'no-message)
+        (should
+         (setq file-notify--test-desc
+               (file-notify-add-watch
+                file-notify--test-tmpfile
+                '(change) #'file-notify--test-event-handler)))
+        (should (file-notify-valid-p file-notify--test-desc))
+        (file-notify--test-with-events '(changed)
+          ;; There shouldn't be any problem, because the file is kept.
+          (with-temp-buffer
+            (let ((buffer-file-name file-notify--test-tmpfile)
+                  (make-backup-files t)
+                  (backup-by-copying t)
+                  (kept-new-versions 1)
+                  (delete-old-versions t))
+              (insert "another text")
+              (save-buffer))))
+        ;; After saving the buffer, the descriptor is still valid.
+        (should (file-notify-valid-p file-notify--test-desc))
+        (delete-file file-notify--test-tmpfile))
+
+    ;; Cleanup.
+    (file-notify--test-cleanup))
+
+  (unwind-protect
+      (progn
+        (setq file-notify--test-tmpfile (file-notify--test-make-temp-name))
+        (write-region "any text" nil file-notify--test-tmpfile nil 'no-message)
+        (should
+         (setq file-notify--test-desc
+               (file-notify-add-watch
+                file-notify--test-tmpfile
+                '(change) #'file-notify--test-event-handler)))
+        (should (file-notify-valid-p file-notify--test-desc))
+        (file-notify--test-with-events '(renamed created changed)
+          ;; The file is renamed when creating a backup.  It shall
+          ;; still be watched.
+          (with-temp-buffer
+            (let ((buffer-file-name file-notify--test-tmpfile)
+                  (make-backup-files t)
+                  (backup-by-copying nil)
+                  (backup-by-copying-when-mismatch nil)
+                  (kept-new-versions 1)
+                  (delete-old-versions t))
+              (insert "another text")
+              (save-buffer))))
+        ;; After saving the buffer, the descriptor is still valid.
+        (should (file-notify-valid-p file-notify--test-desc))
+        (delete-file file-notify--test-tmpfile))
+
+    ;; Cleanup.
+    (file-notify--test-cleanup)))
+
+(file-notify--deftest-remote file-notify-test07-backup
+  "Check that backup keeps file supervision for remote files.")
+
 (defun file-notify-test-all (&optional interactive)
   "Run all tests for \\[file-notify]."
   (interactive "p")