vc-git--program-version to support Git for macOS version string

`git version` on macOS returns e.g., "git version 2.30.1 (Apple
Git-130)" and `vc-git--program-version` currently returns "0" instead
of "2.30.1".

* lisp/vc/vc-git.el (vc-git--program-version): Ignore text after
the version number when parsing git versions (bug#52172).

Copyright-paperwork-exempt: yes

1 files changed, 67 insertions, 0 deletions

diff --git a/test/lisp/vc/vc-git-tests.el b/test/lisp/vc/vc-git-tests.el
new file mode 100644
index 00000000000..997ab3c4b5c
--- /dev/null
+++ b/test/lisp/vc/vc-git-tests.el
@@ -0,0 +1,67 @@
+;;; vc-git-tests.el --- tests for vc/vc-git.el  -*- lexical-binding:t -*-
+
+;; Copyright (C) 2016-2021 Free Software Foundation, Inc.
+
+;; Author: Justin Schell <justinmschell@gmail.com>
+;; Maintainer: emacs-devel@gnu.org
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;; Code:
+
+(require 'vc-git)
+
+(ert-deftest vc-git-test-program-version-general ()
+  (vc-git-test--run-program-version-test
+   "git version 2.30.1.0"
+   "2.30.1.0"))
+
+(ert-deftest vc-git-test-program-version-windows ()
+  (vc-git-test--run-program-version-test
+   "git version 2.30.1.1.windows.1"
+   "2.30.1.1"))
+
+(ert-deftest vc-git-test-program-version-apple ()
+  (vc-git-test--run-program-version-test
+   "git version 2.30.1.2 (Apple Git-130)"
+   "2.30.1.2"))
+
+(ert-deftest vc-git-test-program-version-other ()
+  (vc-git-test--run-program-version-test
+   "git version 2.30.1.3.foo.bar"
+   "2.30.1.3"))
+
+(ert-deftest vc-git-test-program-version-invalid-leading-string ()
+  (vc-git-test--run-program-version-test
+   "git version foo.bar.2.30.1.4"
+   "0"))
+
+(ert-deftest vc-git-test-program-version-invalid-leading-dot ()
+  (vc-git-test--run-program-version-test
+   "git version .2.30.1.5"
+   "0"))
+
+(defun vc-git-test--run-program-version-test
+    (mock-version-string expected-output)
+  (cl-letf* (((symbol-function 'vc-git--run-command-string)
+              (lambda (_file _args) mock-version-string))
+             (vc-git--program-version nil)
+             (actual-output (vc-git--program-version)))
+    (should (equal actual-output expected-output))))
+
+;;; vc-git-tests.el ends here