[PATCH] contrib: added git-diffall

[Tim Henigan <tim.henigan@gmail.com>]

This script adds directory diff support to git.  It launches a single
instance of the user-configured external diff tool and performs a
directory diff between the specified revisions. The before/after files
are copied to a tmp directory to do this.  Either 'diff.tool' or
'merge.tool' must be set before running the script.

The existing 'git difftool' command already allows the user to view diffs
using an external tool.  However if multiple files have changed, a
separate instance of the tool is launched for each one.  This can be
tedious when many files are involved.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
---

This script has been hosted on GitHub [1] since April 2010. Enough people
have found it useful that I hope it will be considered for inclusion in
the standard git install, either in contrib or as a new core command.

[1]: https://github.com/thenigan/git-diffall

 contrib/diffall/README      |   18 +++
 contrib/diffall/git-diffall |  275 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 293 insertions(+)
 create mode 100644 contrib/diffall/README
 create mode 100755 contrib/diffall/git-diffall

diff --git a/contrib/diffall/README b/contrib/diffall/README
new file mode 100644
index 0000000..12881d2
--- /dev/null
+++ b/contrib/diffall/README
@@ -0,0 +1,18 @@
+The git-diffall script provides a directory based diff mechanism
+for git.  The script relies on the diff.tool configuration option
+to determine what diff viewer is used.
+
+This script is compatible with all the forms used to specify a
+range of revisions to diff:
+
+  1. git diffall: shows diff between working tree and staged changes
+  2. git diffall --cached [<commit>]: shows diff between staged changes and HEAD (or other named commit)
+  3. git diffall <commit>: shows diff between working tree and named commit
+  4. git diffall <commit> <commit>: show diff between two named commits
+  5. git diffall <commit>..<commit>: same as above
+  6. git diffall <commit>...<commit>: show the changes on the branch containing and up to the second , starting at a common ancestor of both <commit>
+
+Note: all forms take an optional path limiter [--] [<path>*]
+
+This script is based on an example provided by Thomas Rast on the Git list [1]:
+[1] http://thread.gmane.org/gmane.comp.version-control.git/124807
diff --git a/contrib/diffall/git-diffall b/contrib/diffall/git-diffall
new file mode 100755
index 0000000..ef01eda
--- /dev/null
+++ b/contrib/diffall/git-diffall
@@ -0,0 +1,275 @@
+#!/bin/bash -e
+# Copyright 2010 - 2012, Tim Henigan <tim.henigan@gmail.com>
+#
+# Perform a directory diff between commits in the repository using
+# the external diff or merge tool specified in the user's config.
+
+USAGE='[--cached] [--copy-back] [-x|--extcmd=<command>] <commit>{0,2} -- <path>*
+
+    --cached     Compare to the index rather than the working tree.
+
+    --copy-back  Copy files back to the working tree when the diff
+                 tool exits (in case they were modified by the
+                 user).  This option is only valid if the diff
+                 compared with the working tree.
+
+    -x=<command>
+    --extcmd=<command>  Specify a custom command for viewing diffs.
+                 git-diffall ignores the configured defaults and
+                 runs $command $LOCAL $REMOTE when this option is
+                 specified. Additionally, $BASE is set in the
+                 environment.
+'
+
+SUBDIRECTORY_OK=1
+. "$(git --exec-path)/git-sh-setup"
+
+TOOL_MODE=diff
+. "$(git --exec-path)/git-mergetool--lib"
+
+merge_tool="$(get_merge_tool)"
+if test -z "$merge_tool"
+then
+	echo "Error: Either the 'diff.tool' or 'merge.tool' option must be set."
+	usage
+fi
+
+start_dir=$(pwd)
+
+# needed to access tar utility
+cdup=$(git rev-parse --show-cdup) &&
+cd "$cdup" || {
+	echo >&2 "Cannot chdir to $cdup, the toplevel of the working tree"
+	exit 1
+}
+
+# mktemp is not available on all platforms (missing from msysgit)
+# Use a hard-coded tmp dir if it is not available
+if test -z $(which mktemp 2>/dev/null)
+then
+	tmp=/tmp/git-diffall-tmp
+else
+	tmp="$(mktemp -d -t tmp.XXXXXX)"
+fi
+mkdir -p "$tmp"
+
+left=
+right=
+paths=
+path_sep=
+compare_staged=
+common_ancestor=
+left_dir=
+right_dir=
+diff_tool=
+copy_back=
+
+while test $# != 0
+do
+	case "$1" in
+	-h|--h|--he|--hel|--help)
+		usage
+		;;
+	--cached)
+		compare_staged=1
+		;;
+	--copy-back)
+		copy_back=1
+		;;
+	-x|--e|--ex|--ext|--extc|--extcm|--extcmd)
+		diff_tool=$2
+		shift
+		;;
+	--)
+		path_sep=1
+		;;
+	-*)
+		echo Invalid option: "$1"
+		usage
+		;;
+	*)
+		# could be commit, commit range or path limiter
+		case "$1" in
+		*...*)
+			left=${1%...*}
+			right=${1#*...}
+			common_ancestor=1
+			;;
+		*..*)
+			left=${1%..*}
+			right=${1#*..}
+			;;
+		*)
+			if test -n "$path_sep"
+			then
+				if test -z "$paths"
+				then
+					paths=$1
+				else
+					paths="$paths $1"
+				fi
+			elif test -z "$left"
+			then
+				left=$1
+			elif test -z "$right"
+			then
+				right=$1
+			else
+				if test -z "$paths"
+				then
+					paths=$1
+				else
+					paths="$paths $1"
+				fi
+			fi
+			;;
+		esac
+		;;
+	esac
+	shift
+done
+
+# Determine the set of files which changed
+if test -n "$left" && test -n "$right"
+then
+	left_dir="cmt-$(git rev-parse --short $left)"
+	right_dir="cmt-$(git rev-parse --short $right)"
+
+	if test -n "$compare_staged"
+	then
+		usage
+	elif test -n "$common_ancestor"
+	then
+		git diff --name-only "$left"..."$right" -- $paths > "$tmp"/filelist
+	else
+		git diff --name-only "$left" "$right" -- $paths > "$tmp"/filelist
+	fi
+elif test -n "$left"
+then
+	left_dir="cmt-$(git rev-parse --short $left)"
+
+	if test -n "$compare_staged"
+	then
+		right_dir="staged"
+		git diff --name-only --cached "$left" -- $paths > "$tmp"/filelist
+	else
+		right_dir="working_tree"
+		git diff --name-only "$left" -- $paths > "$tmp"/filelist
+	fi
+else
+	left_dir="HEAD"
+
+	if test -n "$compare_staged"
+	then
+		right_dir="staged"
+		git diff --name-only --cached -- $paths > "$tmp"/filelist
+	else
+		right_dir="working_tree"
+		git diff --name-only -- $paths > "$tmp"/filelist
+	fi
+fi
+
+# Exit immediately if there are no diffs
+if test ! -s "$tmp"/filelist
+then
+	exit 0
+fi
+
+if test -n "$copy_back" && test "$right_dir" != "working_tree"
+then
+	echo "--copy-back is only valid when diff includes the working tree."
+	exit 1
+fi
+
+# Create the named tmp directories that will hold the files to be compared
+mkdir -p "$tmp"/"$left_dir" "$tmp"/"$right_dir"
+
+# Populate the tmp/right_dir directory with the files to be compared
+if test -n "$right"
+then
+	while read name
+	do
+		ls_list=$(git ls-tree $right $name)
+		if test -n "$ls_list"
+	then
+			mkdir -p "$tmp"/"$right_dir"/"$(dirname "$name")"
+			git show "$right":"$name" > "$tmp"/"$right_dir"/"$name" || true
+		fi
+	done < "$tmp"/filelist
+elif test -n "$compare_staged"
+then
+	while read name
+	do
+		ls_list=$(git ls-files -- $name)
+		if test -n "$ls_list"
+	then
+			mkdir -p "$tmp"/"$right_dir"/"$(dirname "$name")"
+			git show :"$name" > "$tmp"/"$right_dir"/"$name"
+		fi
+	done < "$tmp"/filelist
+else
+	if test -n "$(which gnutar 2>/dev/null)"
+	then
+		gnutar --ignore-failed-read -c -T "$tmp"/filelist | (cd "$tmp"/"$right_dir" && gnutar -x)
+	else
+		tar --ignore-failed-read -c -T "$tmp"/filelist | (cd "$tmp"/"$right_dir" && tar -x)
+	fi
+fi
+
+# Populate the tmp/left_dir directory with the files to be compared
+while read name
+do
+	if test -n "$left"
+	then
+		ls_list=$(git ls-tree $left $name)
+		if test -n "$ls_list"
+		then
+			mkdir -p "$tmp"/"$left_dir"/"$(dirname "$name")"
+			git show "$left":"$name" > "$tmp"/"$left_dir"/"$name" || true
+		fi
+	else
+		if test -n "$compare_staged"
+		then
+			ls_list=$(git ls-tree HEAD $name)
+			if test -n "$ls_list"
+			then
+				mkdir -p "$tmp"/"$left_dir"/"$(dirname "$name")"
+				git show HEAD:"$name" > "$tmp"/"$left_dir"/"$name"
+				fi
+			else
+				mkdir -p "$tmp"/"$left_dir"/"$(dirname "$name")"
+				git show :"$name" > "$tmp"/"$left_dir"/"$name"
+		fi
+	fi
+done < "$tmp"/filelist
+
+cd "$tmp"
+LOCAL="$left_dir"
+REMOTE="$right_dir"
+
+if test -n "$diff_tool"
+then
+	export BASE
+	eval $diff_tool '"$LOCAL"' '"$REMOTE"'
+else
+	run_merge_tool "$merge_tool" false
+fi
+
+# This function is called on exit
+cleanup () {
+	cd "$start_dir"
+
+	# Copy files back to the working dir, if requested
+	if test -n "$copy_back" && test "$right_dir" = "working_tree"
+	then
+		git_top_dir=$(git rev-parse --show-toplevel)
+		find "$tmp/$right_dir" -type f|while read file; do
+			cp "$file" "$git_top_dir/${file#$tmp/$right_dir/}"
+		done
+	fi
+
+	# Remove the tmp directory
+	rm -rf "$tmp"
+}
+
+trap cleanup EXIT
-- 
1.7.9.GIT