Add git-show-branches-script

Often I find myself wanting to do quick branches check when I am
not in the windowing environment and cannot run gitk.

This stupid script shows commits leading to the heads of
interesting branches with indication which ones belong to which
branches, so that fork point is somewhat discernible without
using gitk.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Documentation/git-show-branches-script.txt

+git-show-branches-script(1)
+===========================
+v0.99.4, Aug 2005
+
+NAME
+----
+git-show-branches-script - Show branches and their commits.
+
+SYNOPSIS
+--------
+'git show-branches <reference>...'
+
+DESCRIPTION
+-----------
+Shows the head commits from the named <reference> (or all refs under
+$GIT_DIR/refs/heads), and displays concise list of commit logs
+to show their relationship semi-visually.
+
+OPTIONS
+-------
+<reference>::
+	Name of the reference under $GIT_DIR/refs/heads/.
+
+
+OUTPUT
+------
+Given N <references>, the first N lines are the one-line
+description from their commit message.  The branch head that is
+pointed at by $GIT_DIR/HEAD is prefixed with an asterisk '*'
+character while other heads are prefixed with a '!' character.
+
+Following these N lines, one-line log for each commit is
+displayed, indented N places.  If a commit is on the I-th
+branch, the I-th indentation character shows a '+' sign;
+otherwise it shows a space.
+
+The following example shows three branches, "pu", "master" and
+"rc":
+
+	* [pu] Add cheap local clone '-s' flag to git-clone-script
+	 ! [master] Documentation updates.
+	  ! [rc] Merge master into rc
+	+   Add cheap local clone '-s' flag to git-clone-script
+	+   Alternate object pool mechanism updates.
+	+   Audit rev-parse users.
+	++  Documentation updates.
+	  + Merge master into rc
+	+++ [PATCH] plug memory leak in diff.c::diff_free_filepair()
+
+These three branches all forked from a common commit, "[PATCH]
+plug memory leak...", and "rc" has one commit ahead of it.  The
+"master" branch has one different commit that is also shared by
+"pu" branch, and "pu" branch has three more commits on top of
+"master" branch.
+
+
+Author
+------
+Written by Junio C Hamano <junkio@cox.net>
+
+
+Documentation
+--------------
+Documentation by Junio C Hamano.
+
+
+GIT
+---
+Part of the link:git.html[git] suite

Documentation/git.txt

@@ -188,6 +188,8 @@ link:git-pull-script.html[git-pull-script]::
 link:git-commit-script.html[git-commit-script]::
 	Record changes to the repository.
 
+link:git-show-branches-script.html[git-show-branches-script]::
+	Show branches and their commits.
 
 Ancilliary Commands
 -------------------

Makefile

@@ -71,6 +71,7 @@ SCRIPTS=git git-apply-patch-script git-merge-one-file-script git-prune-script \
 SCRIPTS += git-count-objects-script
 # SCRIPTS += git-send-email-script
 SCRIPTS += git-revert-script
+SCRIPTS += git-show-branches-script
 
 PROG=   git-update-cache git-diff-files git-init-db git-write-tree \
 	git-read-tree git-commit-tree git-cat-file git-fsck-cache \

git-show-branches-script

+#!/bin/sh
+#
+# Show refs and their recent commits.
+#
+
+. git-sh-setup-script || die "Not a git repository"
+
+headref=`readlink $GIT_DIR/HEAD`
+case "$#" in
+0)
+	set x `cd $GIT_DIR/refs &&
+	    find heads -type f -print |
+	    sed -e 's|heads/||' |
+	    sort`
+	shift ;;
+esac
+
+hh= in=
+for ref
+do
+	case "/$headref" in
+	*/"$ref") H='*' ;;
+	*) H='!' ;;
+	esac
+	h=`git-rev-parse --verify "$ref^0"` || exit
+	l=`git-log-script --max-count=1 --pretty=oneline "$h" |
+		sed -e 's/^[^ ]* //'`
+	hh="$hh $h"
+	echo "$in$H [$ref] $l"
+	in="$in "
+done
+set x $hh
+shift
+
+git-rev-list --pretty=oneline "$@" |
+while read v l
+do
+	in=''
+	for h
+	do
+		b=`git-merge-base $h $v`
+		case "$b" in
+		$v) in="$in+" ;;
+		*)  in="$in " ;;
+		esac
+	done
+
+	echo "$in $l"
+	case "$in" in
+	*' '*) ;;
+	*) break ;;
+	esac
+done