From 5bb26c63843381d9b3dad7708970a93494d20b26 Mon Sep 17 00:00:00 2001
From: Tom Willemse <tom@ryuslash.org>
Date: Mon, 7 Oct 2019 21:29:12 -0700
Subject: [PATCH] =?UTF-8?q?Don=E2=80=99t=20commit=20when=20there=20are=20n?=
 =?UTF-8?q?o=20changes?=
MIME-Version: 1.0
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Before trying to commit, run a ‘git diff’ to make sure there are any changes to
commit. If this turns up empty no commit is attempted.
---
 NEWS                    |  6 ++++++
 git-auto-commit-mode.el | 12 +++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/NEWS b/NEWS
index cd903a6..1409bfb 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,12 @@
 # -*- mode: org; -*-
 #+STARTUP: showall
 
+* Unreleased
+
+  - Only try to commit when changes have been discovered in the file. By
+    extension git-auto-commit-mode won't ask for a summary to a commit that it
+    won't make.
+
 * v4.5.0
 
   - Support the fish shell through the ~gac-shell-and~ option.
diff --git a/git-auto-commit-mode.el b/git-auto-commit-mode.el
index 917b748..33ffa1a 100644
--- a/git-auto-commit-mode.el
+++ b/git-auto-commit-mode.el
@@ -164,9 +164,19 @@ should already have been set up."
                             actual-buffer)
                gac--debounce-timers))))
 
+(defun gac--buffer-has-changes (buffer)
+  "Check to see if there is any change in BUFFER."
+  (let ((file-name (convert-standard-filename
+                    (file-name-nondirectory
+                     (buffer-file-name buffer)))))
+    (not (string=
+          (shell-command-to-string (concat "git diff " file-name))
+          ""))))
+
 (defun gac--after-save (buffer)
   (unwind-protect
-      (when (buffer-live-p buffer)
+      (when (and (buffer-live-p buffer)
+                 (gac--buffer-has-changes buffer))
         (gac-commit buffer)
         (with-current-buffer buffer
           ;; with-current-buffer required here because gac-automatically-push-p