[PATCH] format-patch: give an overview of what a "patch" message is

From: Bagas Sanjaya <bagasdotme@gmail.com>
Date: Mar 25, 2021, 10:54 UTC
Message-ID: <20210325105433.43310-1-bagasdotme@gmail.com>

The text says something called a "patch" is prepared one for each commit, it is suitable for e-mail submission, and "am" is the command to use it, but does not say what the "patch" really is. The description in the page also refers to "three-dash" line, but that is totally unclear unless the reader is given a more detailed overview of what the "patch" the first paragraph refers to.

Co-authored-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
---

This patch is from discussion on [1]. Junio said that rather than add a new section describing the format of format-patch generated patches, extend the first paragraph of Description to better reflect that format.

[1]: https://lore.kernel.org/git/xmqqeeg4zbyz.fsf@gitster.g/

 Documentation/git-format-patch.txt | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 3e49bf2210..5cd8578b6f 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -36,11 +36,28 @@ SYNOPSIS
 DESCRIPTION
 -----------
 
-Prepare each commit with its patch in
-one file per commit, formatted to resemble UNIX mailbox format.
+Prepare each commit with its "patch" in
+one "message" per commit, formatted to resemble a UNIX mailbox.
 The output of this command is convenient for e-mail submission or
 for use with 'git am'.
 
+A "message" generated by the command consists of three parts:
+
+* A brief metadata header that begins with `From <commit>`
+  with a fixed `Mon Sep 17 00:00:00 2001` datestamp to help programs
+  like "file(1)" to recognize that the file is an output from this
+  command, fields that record the author identity, the author date,
+  and the title of the change (taken from the first paragraph of the
+  commit log message).
+
+* The second and subsequent paragraphs of the commit log message.
+
+* The "patch", which is the "diff -p --stat" output (see
+  linkgit:git-diff[1]) between the commit and its parent.
+
+The log message and the patch is separated by a line with a
+three-dash line.
+
 There are two ways to specify which commits to operate on.
 
 1. A single commit, <since>, specifies that the commits leading

-- 
2.25.1