New display of outgoing revisions count in VC-Dir

This relies on how vc--incoming-revision now caches incoming
revisions.

* lisp/vc/vc.el (vc--count-outgoing): New function.
* lisp/vc/vc-dir.el (vc-dir-header-urgent-value): New face.
(vc-dir-outgoing-revisions-map): New keymap.
(vc-dir-headers): Use them.
* etc/NEWS: Document the change.

etc/NEWS

@@ -2529,6 +2529,11 @@ bindings:
 - 'C-x v O L' is bound to 'vc-log-outgoing'
 - 'C-x v O D' is bound to 'vc-root-diff-outgoing'.
 
+---
+*** New display of outgoing revisions count in VC-Dir.
+If there are outgoing revisions, VC-Dir now includes a count of how many
+in its headers, to remind you to push them.
+
 +++
 *** New user option 'vc-async-checkin' to enable async checkin operations.
 Currently only supported by the Git and Mercurial backends.

lisp/vc/vc-dir.el

@@ -64,6 +64,11 @@ See `run-hooks'."
   :group 'vc
   :version "28.1")
 
+(defface vc-dir-header-urgent-value '((t :inherit font-lock-warning-face))
+  "Face for urgent header values in VC-Dir buffers."
+  :group 'vc
+  :version "31.1")
+
 (defface vc-dir-directory '((t :inherit font-lock-comment-delimiter-face))
   "Face for directories in VC-Dir buffers."
   :group 'vc
@@ -1328,19 +1333,31 @@ the *vc-dir* buffer.
     (hack-dir-local-variables-non-file-buffer)
     (vc-dir-refresh)))
 
+(defvar-keymap vc-dir-outgoing-revisions-map
+  :doc "Local keymap for viewing outgoing revisions."
+  "<down-mouse-1>" #'vc-log-outgoing)
+
 (defun vc-dir-headers (backend dir)
-  "Display the headers in the *VC dir* buffer.
+  "Display the headers in the *VC-Dir* buffer.
 It calls the `dir-extra-headers' backend method to display backend
 specific headers."
   (concat
-   ;; First layout the common headers.
    (propertize "VC backend : " 'face 'vc-dir-header)
    (propertize (format "%s\n" backend) 'face 'vc-dir-header-value)
    (propertize "Working dir: " 'face 'vc-dir-header)
    (propertize (format "%s\n" (abbreviate-file-name dir))
                'face 'vc-dir-header-value)
-   ;; Then the backend specific ones.
    (vc-call-backend backend 'dir-extra-headers dir)
+   (and-let* ((count (ignore-errors (vc--count-outgoing backend)))
+              (_ (plusp count)))
+     (concat (propertize "\nOutgoing   : "
+                         'face 'vc-dir-header)
+             (propertize (format "%d unpushed revisions\n" count)
+                         'face 'vc-dir-header-urgent-value
+                         'mouse-face 'highlight
+                         'keymap vc-dir-outgoing-revisions-map
+                         'help-echo "\\<vc-dir-outgoing-revisions-map>\
+\\[vc-log-outgoing]: List outgoing revisions")))
    "\n"))
 
 (defun vc-dir-refresh-files (files)

lisp/vc/vc.el

@@ -4077,6 +4077,17 @@ can be a remote branch name."
                        ""
                        (vc-call-backend backend 'mergebase incoming)))))
 
+(defun vc--count-outgoing (backend)
+  "Return number of changes that will be sent with a `vc-push'."
+  (with-temp-buffer
+    (let ((display-buffer-overriding-action
+           '(display-buffer-no-window (allow-no-window . t))))
+      (vc-incoming-outgoing-internal backend nil
+                                     (current-buffer) 'log-outgoing))
+    (let ((proc (get-buffer-process (current-buffer))))
+      (while (accept-process-output proc)))
+    (how-many log-view-message-re)))
+
 ;;;###autoload
 (defun vc-log-search (pattern)
   "Search the VC log of changes for PATTERN and show log of matching changes.

test/lisp/time-stamp-tests.el

@@ -164,7 +164,7 @@
   (iter-yield-from (time-stamp-test-pattern-sequential))
   (iter-yield-from (time-stamp-test-pattern-multiply)))
 
-(ert-deftest time-stamp-custom-start ()
+(ert-deftest time-stamp-custom-start-0 ()
   "Test that `time-stamp' isn't stuck by a start matching 0 characters."
   (with-time-stamp-test-env
     (with-time-stamp-test-time ref-time1
@@ -189,6 +189,18 @@
           (time-stamp)
           (should (equal (buffer-string) "::05::05")))))))
 
+(ert-deftest time-stamp-custom-start-multiline ()
+  "Test `time-stamp-start' matching across multiple lines."
+  (with-time-stamp-test-env
+    (with-time-stamp-test-time ref-time1
+      (let ((time-stamp-pattern "l.1\n%Y-%m-%d<-TS")) ;start includes newline
+        (with-temp-buffer
+          (insert "l.1\n<-TS\n")
+          ;; we should look for the end on the line where the start ends,
+          ;; not the line where the start starts
+          (time-stamp)
+          (should (equal (buffer-string) "l.1\n2006-01-02<-TS\n")))))))
+
 (ert-deftest time-stamp-custom-pattern ()
   "Test that `time-stamp-pattern' is parsed correctly."
   (iter-do (pattern-parts (time-stamp-test-pattern-all))