Merge branch 'jw/doc-commit-title' into maint

* jw/doc-commit-title:
  Documentation: describe subject more precisely

Documentation/git-commit.txt

@@ -389,8 +389,10 @@ DISCUSSION
 Though not required, it's a good idea to begin the commit message
 with a single short (less than 50 character) line summarizing the
 change, followed by a blank line and then a more thorough description.
-Tools that turn commits into email, for example, use the first line
-on the Subject: line and the rest of the commit in the body.
+The text up to the first blank line in a commit message is treated
+as the commit title, and that title is used throughout git.
+For example, linkgit:git-format-patch[1] turns a commit into email, and it uses
+the title on the Subject line and the rest of the commit in the body.
 
 include::i18n.txt[]
 

Documentation/git-for-each-ref.txt

@@ -102,9 +102,10 @@ Fields that have name-email-date tuple as its value (`author`,
 and `date` to extract the named component.
 
 The complete message in a commit and tag object is `contents`.
-Its first line is `contents:subject`, the remaining lines
-are `contents:body` and the optional GPG signature
-is `contents:signature`.
+Its first line is `contents:subject`, where subject is the concatenation
+of all lines of the commit message up to the first blank line.  The next
+line is 'contents:body', where body is all of the lines after the first
+blank line.  Finally, the optional GPG signature is `contents:signature`.
 
 For sorting purposes, fields with numeric values sort in numeric
 order (`objectsize`, `authordate`, `committerdate`, `taggerdate`).

Documentation/git-format-patch.txt

@@ -58,10 +58,13 @@ output, unless the `--stdout` option is specified.
 If `-o` is specified, output files are created in <dir>.  Otherwise
 they are created in the current working directory.
 
-By default, the subject of a single patch is "[PATCH] First Line" and
-the subject when multiple patches are output is "[PATCH n/m] First
-Line". To force 1/1 to be added for a single patch, use `-n`.  To omit
-patch numbers from the subject, use `-N`.
+By default, the subject of a single patch is "[PATCH] " followed by
+the concatenation of lines from the commit message up to the first blank
+line (see the DISCUSSION section of linkgit:git-commit[1]).
+
+When multiple patches are output, the subject prefix will instead be
+"[PATCH n/m] ".  To force 1/1 to be added for a single patch, use `-n`.
+To omit patch numbers from the subject, use `-N`.
 
 If given `--thread`, `git-format-patch` will generate `In-Reply-To` and
 `References` headers to make the second and subsequent patch mails appear

Documentation/git-shortlog.txt

@@ -14,8 +14,7 @@ git log --pretty=short | 'git shortlog' [-h] [-n] [-s] [-e] [-w]
 DESCRIPTION
 -----------
 Summarizes 'git log' output in a format suitable for inclusion
-in release announcements. Each commit will be grouped by author and
-the first line of the commit message will be shown.
+in release announcements. Each commit will be grouped by author and title.
 
 Additionally, "[PATCH]" will be stripped from the commit description.
 

Documentation/gitcore-tutorial.txt

@@ -956,12 +956,11 @@ $ git show-branch --topo-order --more=1 master mybranch
 ------------------------------------------------
 
 The first two lines indicate that it is showing the two branches
-and the first line of the commit log message from their
-top-of-the-tree commits, you are currently on `master` branch
-(notice the asterisk `*` character), and the first column for
-the later output lines is used to show commits contained in the
+with the titles of their top-of-the-tree commits, you are currently on
+`master` branch (notice the asterisk `*` character), and the first
+column for the later output lines is used to show commits contained in the
 `master` branch, and the second column for the `mybranch`
-branch. Three commits are shown along with their log messages.
+branch. Three commits are shown along with their titles.
 All of them have non blank characters in the first column (`*`
 shows an ordinary commit on the current branch, `-` is a merge commit), which
 means they are now part of the `master` branch. Only the "Some

Documentation/gittutorial.txt

@@ -139,9 +139,11 @@ them to the index, and commit, all in one step.
 A note on commit messages: Though not required, it's a good idea to
 begin the commit message with a single short (less than 50 character)
 line summarizing the change, followed by a blank line and then a more
-thorough description.  Tools that turn commits into email, for
-example, use the first line on the Subject: line and the rest of the
-commit in the body.
+thorough description. The text up to the first blank line in a commit
+message is treated as the commit title, and that title is used
+throughout git.  For example, linkgit:git-format-patch[1] turns a
+commit into email, and it uses the title on the Subject line and the
+rest of the commit in the body.
 
 Git tracks content not files
 ----------------------------

Documentation/user-manual.txt

@@ -1136,9 +1136,12 @@ Creating good commit messages
 Though not required, it's a good idea to begin the commit message
 with a single short (less than 50 character) line summarizing the
 change, followed by a blank line and then a more thorough
-description.  Tools that turn commits into email, for example, use
-the first line on the Subject line and the rest of the commit in the
-body.
+description.  The text up to the first blank line in a commit
+message is treated as the commit title, and that title is used
+throughout git.  For example, linkgit:git-format-patch[1] turns a
+commit into email, and it uses the title on the Subject line and the
+rest of the commit in the body.
+
 
 [[ignoring-files]]
 Ignoring files