From: Juri Linkov <juri@linkov.net>
Date: Sun, 2 Oct 2022 18:50:08 +0000 (+0300)
Subject: * lisp/vc/vc-git.el (vc-git-checkin): Add more checks for vc-git-patch-string
X-Git-Tag: emacs-29.0.90~1856^2~72
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=5e37b27ce9785b7b67506f44318fc56d3ce517e5;p=emacs.git

* lisp/vc/vc-git.el (vc-git-checkin): Add more checks for vc-git-patch-string

Check that vc-git-patch-string contains the same changes that already exists
in the staged area when files were added/removed by vc commands (bug#52349).
---

diff --git a/lisp/vc/vc-git.el b/lisp/vc/vc-git.el
index 9cc1aee6747..4a2a42ad2a7 100644
--- a/lisp/vc/vc-git.el
+++ b/lisp/vc/vc-git.el
@@ -1015,7 +1015,31 @@ It is based on `log-edit-mode', and has Git-specific extensions."
                 (make-nearby-temp-file "git-msg")))))
     (when vc-git-patch-string
       (unless (zerop (vc-git-command nil t nil "diff" "--cached" "--quiet"))
-        (user-error "Index not empty"))
+        ;; Check that all staged changes also exist in the patch.
+        ;; This is needed to allow adding/removing files that are
+        ;; currently staged to the index.  So remove the whole file diff
+        ;; from the patch because commit will take it from the index.
+        (with-temp-buffer
+          (vc-git-command (current-buffer) t nil "diff" "--cached")
+          (goto-char (point-min))
+          (let ((pos (point)) file-diff file-beg)
+            (while (not (eobp))
+              (forward-line 1) ; skip current "diff --git" line
+              (search-forward "diff --git" nil 'move)
+              (move-beginning-of-line 1)
+              (setq file-diff (buffer-substring pos (point)))
+              (if (and (setq file-beg (string-search
+                                       file-diff vc-git-patch-string))
+                       ;; Check that file diff ends with an empty string
+                       ;; or the beginning of the next file diff.
+                       (string-match-p "\\`\\'\\|\\`diff --git"
+                                       (substring
+                                        vc-git-patch-string
+                                        (+ file-beg (length file-diff)))))
+                  (setq vc-git-patch-string
+                        (string-replace file-diff "" vc-git-patch-string))
+                (user-error "Index not empty"))
+              (setq pos (point))))))
       (let ((patch-file (make-temp-file "git-patch")))
         (with-temp-file patch-file
           (insert vc-git-patch-string))