[bug#38738] [PATCH WIP v2] etc: Add "tarball" snippet

[Brett Gilio]

This is a revised (but still ugly) revision of the original snippet that
I think details somewhat what I mean by detecting the relevant changes
to these types of commits and adding something to indicate this. I'd
really like to see this be on the same line, instead of having two
[source] blocks. But, as noted before, not a pro in Yasnippet by any
means. :) (not to mention, the elisp is not good, but it is a rough
concept).

>From 488faa8cabd298bb2d00f91a6056b26227089060 Mon Sep 17 00:00:00 2001
From: Brett Gilio <address@hidden>
Date: Wed, 25 Dec 2019 00:38:37 -0600
Subject: [PATCH] etc: Add "tarball" snippet

* etc/snippets/text-mode/guix-commit-message-unstable-tarball: New file.
---
 .../guix-commit-message-unstable-tarball      | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 etc/snippets/text-mode/guix-commit-message-unstable-tarball

diff --git a/etc/snippets/text-mode/guix-commit-message-unstable-tarball 
b/etc/snippets/text-mode/guix-commit-message-unstable-tarball
new file mode 100644
index 0000000000..6a41d2156a
--- /dev/null
+++ b/etc/snippets/text-mode/guix-commit-message-unstable-tarball
@@ -0,0 +1,20 @@
+# -*- mode: snippet -*-
+# name: guix-commit-message-unstable-tarball
+# key: tarball
+# condition: git-commit-mode
+# --
+gnu: $1: Don't use unstable tarball.
+
+* `(car (magit-staged-files))` ($1): Modify package to use stable git 
references.
+`(with-temp-buffer
+   (magit-git-wash #'magit-diff-wash-diffs
+     "diff" "--staged")
+   (beginning-of-buffer)
+   (when (search-forward "(method git-fetch" nil 'noerror)
+     (print "[source]: Use GIT-FETCH.")))`
+`(with-temp-buffer
+   (magit-git-wash #'magit-diff-wash-diffs
+     "diff" "--staged")
+   (beginning-of-buffer)
+   (when (search-forward "(file-name (git-file-name" nil 'noerror)
+     (print "[source]: Use GIT-FILE-NAME.")))`
-- 
2.24.1