git-{merge,diff}tool refactor round three

git-{merge,diff}tool refactor round three

[David Aguilar]

Hopefully this is the final round =)

This series is based on top of master.

The result of this series gets us to where da/difftool in pu
arrived, but does so in a maintainer-friendly way.

I'm including Markus' patches in this series just so that it's
clear that this series is dependent on it.

Everything before "move 'git-difftool' out of contrib" can be
applied to master directly since it is not involved in the
refactor.

We'll need to revert:
	d3b8cec difftool: move 'git-difftool' out of contrib
to avoid a merge conflict in next.


In case anyone's curious, da/difftool originally
contained 25 commits.  Less is more.

[PATCH 01/14] doc/merge-config: list ecmerge as a built-in merge tool

[David Aguilar]

From: Markus Heidelberg <markus.heidelberg@web.de>

Signed-off-by: Markus Heidelberg <markus.heidelberg@web.de>
---
 Documentation/merge-config.txt |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/Documentation/merge-config.txt b/Documentation/merge-config.txt
index 1ff08ff..9c44af8 100644
--- a/Documentation/merge-config.txt
+++ b/Documentation/merge-config.txt
@@ -22,7 +22,8 @@ merge.stat::
 merge.tool::
 	Controls which merge resolution program is used by
 	linkgit:git-mergetool[1].  Valid built-in values are: "kdiff3",
-	"tkdiff", "meld", "xxdiff", "emerge", "vimdiff", "gvimdiff", and
+	"tkdiff", "meld", "xxdiff", "emerge", "vimdiff", "gvimdiff",
+	"ecmerge" and
 	"opendiff".  Any other value is treated is custom merge tool
 	and there must be a corresponding mergetool.<tool>.cmd option.
 
-- 
1.6.2.2.414.g81aa9

[PATCH 02/14] git-mergetool/difftool: make (g)vimdiff workable under Windows

[David Aguilar]

From: Markus Heidelberg <markus.heidelberg@web.de>

Under Windows vimdiff and gvimdiff are not available as symbolic links,
but as batch files vimdiff.bat and gvimdiff.bat. These files weren't
found by 'type vimdiff' which led to the following error:

    The merge tool vimdiff is not available as 'vimdiff'

Even if they were found, it wouldn't work to invoke these batch files
from git-mergetool.

To solve this, use vim and gvim (vim.exe and gvim.exe) and pass the -d
command line switch over to them.

Signed-off-by: Markus Heidelberg <markus.heidelberg@web.de>
---
 contrib/difftool/git-difftool-helper |   10 ++++++++--
 git-mergetool.sh                     |   10 ++++++++--
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/contrib/difftool/git-difftool-helper b/contrib/difftool/git-difftool-helper
index 9c0a134..e481913 100755
--- a/contrib/difftool/git-difftool-helper
+++ b/contrib/difftool/git-difftool-helper
@@ -86,11 +86,11 @@ launch_merge_tool () {
 		;;
 
 	vimdiff)
-		"$merge_tool_path" -c "wincmd l" "$LOCAL" "$REMOTE"
+		"$merge_tool_path" -d -c "wincmd l" "$LOCAL" "$REMOTE"
 		;;
 
 	gvimdiff)
-		"$merge_tool_path" -c "wincmd l" -f "$LOCAL" "$REMOTE"
+		"$merge_tool_path" -d -c "wincmd l" -f "$LOCAL" "$REMOTE"
 		;;
 
 	xxdiff)
@@ -160,6 +160,12 @@ init_merge_tool_path() {
 	merge_tool_path=$(git config mergetool."$1".path)
 	if test -z "$merge_tool_path"; then
 		case "$1" in
+		vimdiff)
+			merge_tool_path=vim
+			;;
+		gvimdiff)
+			merge_tool_path=gvim
+			;;
 		emerge)
 			merge_tool_path=emacs
 			;;
diff --git a/git-mergetool.sh b/git-mergetool.sh
index 87fa88a..6e611e9 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -214,12 +214,12 @@ merge_file () {
 	    ;;
 	vimdiff)
 	    touch "$BACKUP"
-	    "$merge_tool_path" -c "wincmd l" "$LOCAL" "$MERGED" "$REMOTE"
+	    "$merge_tool_path" -d -c "wincmd l" "$LOCAL" "$MERGED" "$REMOTE"
 	    check_unchanged
 	    ;;
 	gvimdiff)
 	    touch "$BACKUP"
-	    "$merge_tool_path" -c "wincmd l" -f "$LOCAL" "$MERGED" "$REMOTE"
+	    "$merge_tool_path" -d -c "wincmd l" -f "$LOCAL" "$MERGED" "$REMOTE"
 	    check_unchanged
 	    ;;
 	xxdiff)
@@ -359,6 +359,12 @@ init_merge_tool_path() {
 	merge_tool_path=`git config mergetool.$1.path`
 	if test -z "$merge_tool_path" ; then
 		case "$1" in
+			vimdiff)
+				merge_tool_path=vim
+				;;
+			gvimdiff)
+				merge_tool_path=gvim
+				;;
 			emerge)
 				merge_tool_path=emacs
 				;;
-- 
1.6.2.2.414.g81aa9

[PATCH 03/14] git-mergetool: add new merge tool TortoiseMerge

[David Aguilar]

From: Markus Heidelberg <markus.heidelberg@web.de>

TortoiseMerge comes with TortoiseSVN or TortoiseGit for Windows. It can
only be used as a merge tool with an existing base file. It cannot be
used without a base nor as a diff tool.

The documentation only mentions the slash '/' as command line option
prefix, which refused to work, but the parser also accepts the dash '-'

See http://code.google.com/p/msysgit/issues/detail?id=226

Signed-off-by: Markus Heidelberg <markus.heidelberg@web.de>
---
 Documentation/git-mergetool.txt |    3 ++-
 Documentation/merge-config.txt  |    2 +-
 git-mergetool.sh                |   16 +++++++++++++---
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/Documentation/git-mergetool.txt b/Documentation/git-mergetool.txt
index 5d3c632..5edac4d 100644
--- a/Documentation/git-mergetool.txt
+++ b/Documentation/git-mergetool.txt
@@ -26,7 +26,8 @@ OPTIONS
 --tool=<tool>::
 	Use the merge resolution program specified by <tool>.
 	Valid merge tools are:
-	kdiff3, tkdiff, meld, xxdiff, emerge, vimdiff, gvimdiff, ecmerge, and opendiff
+	kdiff3, tkdiff, meld, xxdiff, emerge, vimdiff, gvimdiff, ecmerge,
+	tortoisemerge and opendiff
 +
 If a merge resolution program is not specified, 'git-mergetool'
 will use the configuration variable `merge.tool`.  If the
diff --git a/Documentation/merge-config.txt b/Documentation/merge-config.txt
index 9c44af8..8c10f66 100644
--- a/Documentation/merge-config.txt
+++ b/Documentation/merge-config.txt
@@ -23,7 +23,7 @@ merge.tool::
 	Controls which merge resolution program is used by
 	linkgit:git-mergetool[1].  Valid built-in values are: "kdiff3",
 	"tkdiff", "meld", "xxdiff", "emerge", "vimdiff", "gvimdiff",
-	"ecmerge" and
+	"ecmerge", tortoisemerge and
 	"opendiff".  Any other value is treated is custom merge tool
 	and there must be a corresponding mergetool.<tool>.cmd option.
 
diff --git a/git-mergetool.sh b/git-mergetool.sh
index 6e611e9..be9717a 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -265,6 +265,16 @@ merge_file () {
 	    fi
 	    status=$?
 	    ;;
+	tortoisemerge)
+	    if base_present ; then
+		touch "$BACKUP"
+		"$merge_tool_path" -base:"$BASE" -mine:"$LOCAL" -theirs:"$REMOTE" -merged:"$MERGED"
+		check_unchanged
+	    else
+		echo "TortoiseMerge cannot be used without a base" 1>&2
+		status=1
+	    fi
+	    ;;
 	*)
 	    if test -n "$merge_tool_cmd"; then
 		if test "$merge_tool_trust_exit_code" = "false"; then
@@ -345,7 +355,7 @@ valid_custom_tool()
 
 valid_tool() {
 	case "$1" in
-		kdiff3 | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge)
+		kdiff3 | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge | tortoisemerge)
 			;; # happy
 		*)
 			if ! valid_custom_tool "$1"; then
@@ -404,9 +414,9 @@ fi
 if test -z "$merge_tool" ; then
     if test -n "$DISPLAY"; then
         if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
-            merge_tool_candidates="meld kdiff3 tkdiff xxdiff gvimdiff"
+            merge_tool_candidates="meld kdiff3 tkdiff xxdiff tortoisemerge gvimdiff"
         else
-            merge_tool_candidates="kdiff3 tkdiff xxdiff meld gvimdiff"
+            merge_tool_candidates="kdiff3 tkdiff xxdiff meld tortoisemerge gvimdiff"
         fi
     fi
     if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then
-- 
1.6.2.2.414.g81aa9

[PATCH 04/14] difftool: remove merge options for opendiff, tkdiff, kdiff3 and xxdiff

[David Aguilar]

We shouldn't try to merge files when using difftool, so remove
any merge-specific options.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 contrib/difftool/git-difftool-helper |   10 +++-------
 1 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/contrib/difftool/git-difftool-helper b/contrib/difftool/git-difftool-helper
index e481913..ef684b6 100755
--- a/contrib/difftool/git-difftool-helper
+++ b/contrib/difftool/git-difftool-helper
@@ -69,7 +69,7 @@ launch_merge_tool () {
 		"$merge_tool_path" --auto \
 			--L1 "$basename (A)" \
 			--L2 "$basename (B)" \
-			-o "$MERGED" "$LOCAL" "$REMOTE" \
+			"$LOCAL" "$REMOTE" \
 			> /dev/null 2>&1
 		;;
 
@@ -78,7 +78,7 @@ launch_merge_tool () {
 		;;
 
 	tkdiff)
-		"$merge_tool_path" -o "$MERGED" "$LOCAL" "$REMOTE"
+		"$merge_tool_path" "$LOCAL" "$REMOTE"
 		;;
 
 	meld)
@@ -95,17 +95,13 @@ launch_merge_tool () {
 
 	xxdiff)
 		"$merge_tool_path" \
-			-X \
-			-R 'Accel.SaveAsMerged: "Ctrl-S"' \
 			-R 'Accel.Search: "Ctrl+F"' \
 			-R 'Accel.SearchForward: "Ctrl-G"' \
-			--merged-file "$MERGED" \
 			"$LOCAL" "$REMOTE"
 		;;
 
 	opendiff)
-		"$merge_tool_path" "$LOCAL" "$REMOTE" \
-			-merge "$MERGED" | cat
+		"$merge_tool_path" "$LOCAL" "$REMOTE" | cat
 		;;
 
 	ecmerge)
-- 
1.6.2.2.414.g81aa9

[PATCH 05/14] difftool: remove the backup file feature

[David Aguilar]

Most users find the backup file feature annoying and there's no
need for it since diff is supposed to be a read-only operation.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 contrib/difftool/git-difftool-helper |   34 +---------------------------------
 1 files changed, 1 insertions(+), 33 deletions(-)

diff --git a/contrib/difftool/git-difftool-helper b/contrib/difftool/git-difftool-helper
index ef684b6..e74a274 100755
--- a/contrib/difftool/git-difftool-helper
+++ b/contrib/difftool/git-difftool-helper
@@ -9,31 +9,7 @@
 
 # Set GIT_DIFFTOOL_NO_PROMPT to bypass the per-file prompt.
 should_prompt () {
-	! test -n "$GIT_DIFFTOOL_NO_PROMPT"
-}
-
-# Should we keep the backup .orig file?
-keep_backup_mode="$(git config --bool merge.keepBackup || echo true)"
-keep_backup () {
-	test "$keep_backup_mode" = "true"
-}
-
-# This function manages the backup .orig file.
-# A backup $MERGED.orig file is created if changes are detected.
-cleanup_temp_files () {
-	if test -n "$MERGED"; then
-		if keep_backup && test "$MERGED" -nt "$BACKUP"; then
-			test -f "$BACKUP" && mv -- "$BACKUP" "$MERGED.orig"
-		else
-			rm -f -- "$BACKUP"
-		fi
-	fi
-}
-
-# This is called when users Ctrl-C out of git-difftool-helper
-sigint_handler () {
-	cleanup_temp_files
-	exit 1
+	test -z "$GIT_DIFFTOOL_NO_PROMPT"
 }
 
 # This function prepares temporary files and launches the appropriate
@@ -47,12 +23,6 @@ launch_merge_tool () {
 	LOCAL="$2"
 	REMOTE="$3"
 	BASE="$1"
-	ext="$$$(expr "$MERGED" : '.*\(\.[^/]*\)$')"
-	BACKUP="$MERGED.BACKUP.$ext"
-
-	# Create and ensure that we clean up $BACKUP
-	test -f "$MERGED" && cp -- "$MERGED" "$BACKUP"
-	trap sigint_handler INT
 
 	# $LOCAL and $REMOTE are temporary files so prompt
 	# the user with the real $MERGED name before launching $merge_tool.
@@ -120,8 +90,6 @@ launch_merge_tool () {
 		fi
 		;;
 	esac
-
-	cleanup_temp_files
 }
 
 # Verifies that (difftool|mergetool).<tool>.cmd exists
-- 
1.6.2.2.414.g81aa9

[PATCH 06/14] difftool: use perl built-ins when testing for msys

[David Aguilar]

I don't even know what $COMSPEC means so let's be safe and use the
same perly $^O test add--interactive uses.  While we're at it, make
git-difftool match the prevalent git-perl style.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 contrib/difftool/git-difftool |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/contrib/difftool/git-difftool b/contrib/difftool/git-difftool
index 0deda3a..207dd50 100755
--- a/contrib/difftool/git-difftool
+++ b/contrib/difftool/git-difftool
@@ -33,7 +33,10 @@ sub setup_environment
 sub exe
 {
 	my $exe = shift;
-	return defined $ENV{COMSPEC} ? "$exe.exe" : $exe;
+	if ($^O eq 'MSWin32' || $^O eq 'msys') {
+		return "$exe.exe";
+	}
+	return $exe;
 }
 
 sub generate_command
@@ -47,7 +50,7 @@ sub generate_command
 			$skip_next = 0;
 			next;
 		}
-		if ($arg eq '-t' or $arg eq '--tool') {
+		if ($arg eq '-t' || $arg eq '--tool') {
 			usage() if $#ARGV <= $idx;
 			$ENV{GIT_DIFF_TOOL} = $ARGV[$idx + 1];
 			$skip_next = 1;
-- 
1.6.2.2.414.g81aa9

[PATCH 07/14] difftool: add a -y shortcut for --no-prompt

[David Aguilar]

This is another consistency cleanup to make git-difftool's options
match git-mergetool.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 contrib/difftool/git-difftool     |    6 +++---
 contrib/difftool/git-difftool.txt |   36 ++++++++++++++----------------------
 2 files changed, 17 insertions(+), 25 deletions(-)

diff --git a/contrib/difftool/git-difftool b/contrib/difftool/git-difftool
index 207dd50..8c160e5 100755
--- a/contrib/difftool/git-difftool
+++ b/contrib/difftool/git-difftool
@@ -18,7 +18,7 @@ my $DIR = abs_path(dirname($0));
 sub usage
 {
 	print << 'USAGE';
-usage: git difftool [--tool=<tool>] [--no-prompt] ["git diff" options]
+usage: git difftool [--tool=<tool>] [-y|--no-prompt] ["git diff" options]
 USAGE
 	exit 1;
 }
@@ -60,11 +60,11 @@ sub generate_command
 			$ENV{GIT_DIFF_TOOL} = substr($arg, 7);
 			next;
 		}
-		if ($arg eq '--no-prompt') {
+		if ($arg eq '-y' || $arg eq '--no-prompt') {
 			$ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
 			next;
 		}
-		if ($arg eq '-h' or $arg eq '--help') {
+		if ($arg eq '-h' || $arg eq '--help') {
 			usage();
 		}
 		push @command, $arg;
diff --git a/contrib/difftool/git-difftool.txt b/contrib/difftool/git-difftool.txt
index 2b7bc03..4dff529 100644
--- a/contrib/difftool/git-difftool.txt
+++ b/contrib/difftool/git-difftool.txt
@@ -3,35 +3,32 @@ git-difftool(1)
 
 NAME
 ----
-git-difftool - compare changes using common merge tools
+git-difftool - Show changes using common diff tools
 
 SYNOPSIS
 --------
-'git difftool' [--tool=<tool>] [--no-prompt] ['git diff' options]
+'git difftool' [-t|--tool=<tool>] [-y|--no-prompt] [<'git diff' options>]
 
 DESCRIPTION
 -----------
 'git-difftool' is a git command that allows you to compare and edit files
-between revisions using common merge tools.  At its most basic level,
-'git-difftool' does what 'git-mergetool' does but its use is for non-merge
-situations such as when preparing commits or comparing changes against
-the index.
-
-'git difftool' is a frontend to 'git diff' and accepts the same
-arguments and options.
-
-See linkgit:git-diff[1] for the full list of supported options.
+between revisions using common diff tools.  'git difftool' is a frontend
+to 'git-diff' and accepts the same options and arguments.
 
 OPTIONS
 -------
+-y::
+--no-prompt::
+	Do not prompt before launching a diff tool.
+
 -t <tool>::
 --tool=<tool>::
-	Use the merge resolution program specified by <tool>.
+	Use the diff tool specified by <tool>.
 	Valid merge tools are:
 	kdiff3, kompare, tkdiff, meld, xxdiff, emerge,
 	vimdiff, gvimdiff, ecmerge, and opendiff
 +
-If a merge resolution program is not specified, 'git-difftool'
+If a diff tool is not specified, 'git-difftool'
 will use the configuration variable `diff.tool`.  If the
 configuration variable `diff.tool` is not set, 'git-difftool'
 will pick a suitable default.
@@ -42,7 +39,7 @@ can configure the absolute path to kdiff3 by setting
 `difftool.kdiff3.path`. Otherwise, 'git-difftool' assumes the
 tool is available in PATH.
 +
-Instead of running one of the known merge tool programs,
+Instead of running one of the known diff tools,
 'git-difftool' can be customized to run an alternative program
 by specifying the command line to invoke in a configuration
 variable `difftool.<tool>.cmd`.
@@ -56,8 +53,7 @@ is set to the name of the temporary file containing the contents
 of the diff post-image.  `$BASE` is provided for compatibility
 with custom merge tool commands and has the same value as `$LOCAL`.
 
---no-prompt::
-	Do not prompt before launching a diff tool.
+See linkgit:git-diff[1] for the full list of supported options.
 
 CONFIG VARIABLES
 ----------------
@@ -65,21 +61,17 @@ CONFIG VARIABLES
 difftool equivalents have not been defined.
 
 diff.tool::
-	The default merge tool to use.
+	The default diff tool to use.
 
 difftool.<tool>.path::
 	Override the path for the given tool.  This is useful in case
 	your tool is not in the PATH.
 
 difftool.<tool>.cmd::
-	Specify the command to invoke the specified merge tool.
+	Specify the command to invoke the specified diff tool.
 +
 See the `--tool=<tool>` option above for more details.
 
-merge.keepBackup::
-	The original, unedited file content can be saved to a file with
-	a `.orig` extension.  Defaults to `true` (i.e. keep the backup files).
-
 SEE ALSO
 --------
 linkgit:git-diff[1]::
-- 
1.6.2.2.414.g81aa9

[PATCH 08/14] difftool/mergetool: add diffuse as merge and diff tool

[David Aguilar]

From: Sebastian Pipping <sebastian@pipping.org>

This adds diffuse as a built-in merge tool.

Signed-off-by: Sebastian Pipping <sebastian@pipping.org>
Signed-off-by: David Aguilar <davvid@gmail.com>
---
 Documentation/git-mergetool.txt        |    2 +-
 Documentation/merge-config.txt         |    2 +-
 contrib/completion/git-completion.bash |    3 ++-
 contrib/difftool/git-difftool-helper   |   10 ++++++----
 contrib/difftool/git-difftool.txt      |    4 ++--
 git-mergetool.sh                       |    4 ++--
 6 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/Documentation/git-mergetool.txt b/Documentation/git-mergetool.txt
index 5edac4d..ff9700d 100644
--- a/Documentation/git-mergetool.txt
+++ b/Documentation/git-mergetool.txt
@@ -27,7 +27,7 @@ OPTIONS
 	Use the merge resolution program specified by <tool>.
 	Valid merge tools are:
 	kdiff3, tkdiff, meld, xxdiff, emerge, vimdiff, gvimdiff, ecmerge,
-	tortoisemerge and opendiff
+	diffuse, tortoisemerge and opendiff
 +
 If a merge resolution program is not specified, 'git-mergetool'
 will use the configuration variable `merge.tool`.  If the
diff --git a/Documentation/merge-config.txt b/Documentation/merge-config.txt
index 8c10f66..4832bc7 100644
--- a/Documentation/merge-config.txt
+++ b/Documentation/merge-config.txt
@@ -23,7 +23,7 @@ merge.tool::
 	Controls which merge resolution program is used by
 	linkgit:git-mergetool[1].  Valid built-in values are: "kdiff3",
 	"tkdiff", "meld", "xxdiff", "emerge", "vimdiff", "gvimdiff",
-	"ecmerge", tortoisemerge and
+	"diffuse", "ecmerge", "tortoisemerge", and
 	"opendiff".  Any other value is treated is custom merge tool
 	and there must be a corresponding mergetool.<tool>.cmd option.
 
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index e72ce24..4fcd77a 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -1173,7 +1173,8 @@ _git_mergetool ()
 	--tool=*)
 		__gitcomp "
 			kdiff3 tkdiff meld xxdiff emerge
-			vimdiff gvimdiff ecmerge opendiff
+			vimdiff gvimdiff ecmerge diffuse
+			opendiff
 			" "" "${cur##--tool=}"
 		return
 		;;
diff --git a/contrib/difftool/git-difftool-helper b/contrib/difftool/git-difftool-helper
index e74a274..4b0daec 100755
--- a/contrib/difftool/git-difftool-helper
+++ b/contrib/difftool/git-difftool-helper
@@ -1,7 +1,5 @@
 #!/bin/sh
 # git-difftool-helper is a GIT_EXTERNAL_DIFF-compatible diff tool launcher.
-# It supports kdiff3, kompare, tkdiff, xxdiff, meld, opendiff,
-# emerge, ecmerge, vimdiff, gvimdiff, and custom user-configurable tools.
 # This script is typically launched by using the 'git difftool'
 # convenience command.
 #
@@ -55,6 +53,10 @@ launch_merge_tool () {
 		"$merge_tool_path" "$LOCAL" "$REMOTE"
 		;;
 
+	diffuse)
+		"$merge_tool_path" "$LOCAL" "$REMOTE" | cat
+		;;
+
 	vimdiff)
 		"$merge_tool_path" -d -c "wincmd l" "$LOCAL" "$REMOTE"
 		;;
@@ -164,9 +166,9 @@ if test -z "$merge_tool"; then
 	if test -n "$DISPLAY"; then
 		# If gnome then prefer meld, otherwise, prefer kdiff3 or kompare
 		if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
-			merge_tool_candidates="meld kdiff3 kompare tkdiff xxdiff gvimdiff"
+			merge_tool_candidates="meld kdiff3 kompare tkdiff xxdiff gvimdiff diffuse"
 		else
-			merge_tool_candidates="kdiff3 kompare tkdiff xxdiff meld gvimdiff"
+			merge_tool_candidates="kdiff3 kompare tkdiff xxdiff meld gvimdiff diffuse"
 		fi
 	fi
 	if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then
diff --git a/contrib/difftool/git-difftool.txt b/contrib/difftool/git-difftool.txt
index 4dff529..a2fa474 100644
--- a/contrib/difftool/git-difftool.txt
+++ b/contrib/difftool/git-difftool.txt
@@ -25,8 +25,8 @@ OPTIONS
 --tool=<tool>::
 	Use the diff tool specified by <tool>.
 	Valid merge tools are:
-	kdiff3, kompare, tkdiff, meld, xxdiff, emerge,
-	vimdiff, gvimdiff, ecmerge, and opendiff
+	kdiff3, kompare, tkdiff, meld, xxdiff, emerge, vimdiff, gvimdiff,
+	ecmerge, diffuse and opendiff
 +
 If a diff tool is not specified, 'git-difftool'
 will use the configuration variable `diff.tool`.  If the
diff --git a/git-mergetool.sh b/git-mergetool.sh
index be9717a..b4d2432 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -414,9 +414,9 @@ fi
 if test -z "$merge_tool" ; then
     if test -n "$DISPLAY"; then
         if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
-            merge_tool_candidates="meld kdiff3 tkdiff xxdiff tortoisemerge gvimdiff"
+            merge_tool_candidates="meld kdiff3 tkdiff xxdiff tortoisemerge gvimdiff diffuse"
         else
-            merge_tool_candidates="kdiff3 tkdiff xxdiff meld tortoisemerge gvimdiff"
+            merge_tool_candidates="kdiff3 tkdiff xxdiff meld tortoisemerge gvimdiff diffuse"
         fi
     fi
     if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then
-- 
1.6.2.2.414.g81aa9

[PATCH 09/14] difftool: move 'git-difftool' out of contrib

[David Aguilar]

This prepares 'git-difftool' and its documentation for
mainstream use.

'git-difftool-helper' became 'git-difftool--helper'
since users should not use it directly.

'git-difftool' was added to the list of commands as
an ancillaryinterrogator.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 .gitignore                                         |    2 ++
 Documentation/config.txt                           |   17 +++++++++++++++++
 .../difftool => Documentation}/git-difftool.txt    |    0
 Makefile                                           |    2 ++
 command-list.txt                                   |    1 +
 .../git-difftool-helper => git-difftool--helper.sh |    2 +-
 contrib/difftool/git-difftool => git-difftool.perl |    6 +++---
 7 files changed, 26 insertions(+), 4 deletions(-)
 rename {contrib/difftool => Documentation}/git-difftool.txt (100%)
 rename contrib/difftool/git-difftool-helper => git-difftool--helper.sh (98%)
 rename contrib/difftool/git-difftool => git-difftool.perl (92%)

diff --git a/.gitignore b/.gitignore
index 1c57d4c..a36da9d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -35,6 +35,8 @@ git-diff
 git-diff-files
 git-diff-index
 git-diff-tree
+git-difftool
+git-difftool--helper
 git-describe
 git-fast-export
 git-fast-import
diff --git a/Documentation/config.txt b/Documentation/config.txt
index ad22cb8..185a9ef 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -667,6 +667,23 @@ diff.suppressBlankEmpty::
 	A boolean to inhibit the standard behavior of printing a space
 	before each empty output line. Defaults to false.
 
+diff.tool::
+	Controls which diff tool is used.  `diff.tool` overrides
+	`merge.tool` when used by linkgit:git-difftool[1] and has
+	the same valid values as `merge.tool`.
+
+difftool.<tool>.path::
+	Override the path for the given tool.  This is useful in case
+	your tool is not in the PATH.
+
+difftool.<tool>.cmd::
+	Specify the command to invoke the specified diff tool.
+	The specified command is evaluated in shell with the following
+	variables available:  'LOCAL' is set to the name of the temporary
+	file containing the contents of the diff pre-image and 'REMOTE'
+	is set to the name of the temporary file containing the contents
+	of the diff post-image.
+
 diff.wordRegex::
 	A POSIX Extended Regular Expression used to determine what is a "word"
 	when performing word-by-word difference calculations.  Character
diff --git a/contrib/difftool/git-difftool.txt b/Documentation/git-difftool.txt
similarity index 100%
rename from contrib/difftool/git-difftool.txt
rename to Documentation/git-difftool.txt
diff --git a/Makefile b/Makefile
index 7867eac..a80055f 100644
--- a/Makefile
+++ b/Makefile
@@ -277,6 +277,7 @@ TEST_PROGRAMS =
 
 SCRIPT_SH += git-am.sh
 SCRIPT_SH += git-bisect.sh
+SCRIPT_SH += git-difftool--helper.sh
 SCRIPT_SH += git-filter-branch.sh
 SCRIPT_SH += git-lost-found.sh
 SCRIPT_SH += git-merge-octopus.sh
@@ -296,6 +297,7 @@ SCRIPT_SH += git-submodule.sh
 SCRIPT_SH += git-web--browse.sh
 
 SCRIPT_PERL += git-add--interactive.perl
+SCRIPT_PERL += git-difftool.perl
 SCRIPT_PERL += git-archimport.perl
 SCRIPT_PERL += git-cvsexportcommit.perl
 SCRIPT_PERL += git-cvsimport.perl
diff --git a/command-list.txt b/command-list.txt
index 3583a33..fb03a2e 100644
--- a/command-list.txt
+++ b/command-list.txt
@@ -33,6 +33,7 @@ git-diff                                mainporcelain common
 git-diff-files                          plumbinginterrogators
 git-diff-index                          plumbinginterrogators
 git-diff-tree                           plumbinginterrogators
+git-difftool                            ancillaryinterrogators
 git-fast-export				ancillarymanipulators
 git-fast-import				ancillarymanipulators
 git-fetch                               mainporcelain common
diff --git a/contrib/difftool/git-difftool-helper b/git-difftool--helper.sh
similarity index 98%
rename from contrib/difftool/git-difftool-helper
rename to git-difftool--helper.sh
index 4b0daec..fc61416 100755
--- a/contrib/difftool/git-difftool-helper
+++ b/git-difftool--helper.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# git-difftool-helper is a GIT_EXTERNAL_DIFF-compatible diff tool launcher.
+# git-difftool--helper is a GIT_EXTERNAL_DIFF-compatible diff tool launcher.
 # This script is typically launched by using the 'git difftool'
 # convenience command.
 #
diff --git a/contrib/difftool/git-difftool b/git-difftool.perl
similarity index 92%
rename from contrib/difftool/git-difftool
rename to git-difftool.perl
index 8c160e5..8857ac8 100755
--- a/contrib/difftool/git-difftool
+++ b/git-difftool.perl
@@ -2,9 +2,9 @@
 # Copyright (c) 2009 David Aguilar
 #
 # This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
-# git-difftool-helper script.  This script exports
+# git-difftool--helper script.  This script exports
 # GIT_EXTERNAL_DIFF and GIT_PAGER for use by git, and
-# GIT_DIFFTOOL_NO_PROMPT and GIT_DIFF_TOOL for use by git-difftool-helper.
+# GIT_DIFFTOOL_NO_PROMPT and GIT_DIFF_TOOL for use by git-difftool--helper.
 # Any arguments that are unknown to this script are forwarded to 'git diff'.
 
 use strict;
@@ -27,7 +27,7 @@ sub setup_environment
 {
 	$ENV{PATH} = "$DIR:$ENV{PATH}";
 	$ENV{GIT_PAGER} = '';
-	$ENV{GIT_EXTERNAL_DIFF} = 'git-difftool-helper';
+	$ENV{GIT_EXTERNAL_DIFF} = 'git-difftool--helper';
 }
 
 sub exe
-- 
1.6.2.2.414.g81aa9

[PATCH 10/14] difftool: add various git-difftool tests

[David Aguilar]

t7800-difftool.sh tests the various command-line flags,
git-config variables, and environment settings supported by
git-difftool.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 t/t7800-difftool.sh |  147 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 147 insertions(+), 0 deletions(-)
 create mode 100755 t/t7800-difftool.sh

diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
new file mode 100755
index 0000000..85946d9
--- /dev/null
+++ b/t/t7800-difftool.sh
@@ -0,0 +1,147 @@
+#!/bin/sh
+#
+# Copyright (c) 2009 David Aguilar
+#
+
+test_description='git-difftool
+
+Testing basic diff tool invocation
+'
+
+. ./test-lib.sh
+
+remove_config_vars()
+{
+	# Unset all config variables used by git-difftool
+	git config --unset diff.tool
+	git config --unset difftool.test-tool.cmd
+	git config --unset merge.tool
+	git config --unset mergetool.test-tool.cmd
+	return 0
+}
+
+restore_test_defaults()
+{
+	# Restores the test defaults used by several tests
+	remove_config_vars
+	unset GIT_DIFF_TOOL
+	unset GIT_MERGE_TOOL
+	unset GIT_DIFFTOOL_NO_PROMPT
+	git config diff.tool test-tool &&
+	git config difftool.test-tool.cmd 'cat $LOCAL'
+}
+
+# Create a file on master and change it on branch
+test_expect_success 'setup' '
+	echo master >file &&
+	git add file &&
+	git commit -m "added file" &&
+
+	git checkout -b branch master &&
+	echo branch >file &&
+	git commit -a -m "branch changed file" &&
+	git checkout master
+'
+
+# Configure a custom difftool.<tool>.cmd and use it
+test_expect_success 'custom commands' '
+	restore_test_defaults &&
+	git config difftool.test-tool.cmd "cat \$REMOTE" &&
+
+	diff=$(git difftool --no-prompt branch) &&
+	test "$diff" = "master" &&
+
+	restore_test_defaults &&
+	diff=$(git difftool --no-prompt branch) &&
+	test "$diff" = "branch"
+'
+
+# Ensures that git-difftool ignores bogus --tool values
+test_expect_success 'difftool ignores bad --tool values' '
+	diff=$(git difftool --no-prompt --tool=bogus-tool branch)
+	test "$?" = 1 &&
+	test "$diff" = ""
+'
+
+# Specify the diff tool using $GIT_DIFF_TOOL
+test_expect_success 'GIT_DIFF_TOOL variable' '
+	git config --unset diff.tool
+	GIT_DIFF_TOOL=test-tool &&
+	export GIT_DIFF_TOOL &&
+
+	diff=$(git difftool --no-prompt branch) &&
+	test "$diff" = "branch" &&
+
+	restore_test_defaults
+'
+
+# Test the $GIT_*_TOOL variables and ensure
+# that $GIT_DIFF_TOOL always wins unless --tool is specified
+test_expect_success 'GIT_DIFF_TOOL overrides' '
+	git config diff.tool bogus-tool &&
+	git config merge.tool bogus-tool &&
+
+	GIT_MERGE_TOOL=test-tool &&
+	export GIT_MERGE_TOOL &&
+	diff=$(git difftool --no-prompt branch) &&
+	test "$diff" = "branch" &&
+	unset GIT_MERGE_TOOL &&
+
+	GIT_MERGE_TOOL=bogus-tool &&
+	GIT_DIFF_TOOL=test-tool &&
+	export GIT_MERGE_TOOL &&
+	export GIT_DIFF_TOOL &&
+
+	diff=$(git difftool --no-prompt branch) &&
+	test "$diff" = "branch" &&
+
+	GIT_DIFF_TOOL=bogus-tool &&
+	export GIT_DIFF_TOOL &&
+
+	diff=$(git difftool --no-prompt --tool=test-tool branch) &&
+	test "$diff" = "branch" &&
+
+	restore_test_defaults
+'
+
+# Test that we don't have to pass --no-prompt to difftool
+# when $GIT_DIFFTOOL_NO_PROMPT is true
+test_expect_success 'GIT_DIFFTOOL_NO_PROMPT variable' '
+	GIT_DIFFTOOL_NO_PROMPT=true &&
+	export GIT_DIFFTOOL_NO_PROMPT &&
+
+	diff=$(git difftool branch) &&
+	test "$diff" = "branch" &&
+
+	restore_test_defaults
+'
+
+# git-difftool falls back to git-mergetool config variables
+# so test that behavior here
+test_expect_success 'difftool + mergetool config variables' '
+	remove_config_vars
+	git config merge.tool test-tool &&
+	git config mergetool.test-tool.cmd "cat \$LOCAL" &&
+
+	diff=$(git difftool --no-prompt branch) &&
+	test "$diff" = "branch" &&
+
+	# set merge.tool to something bogus, diff.tool to test-tool
+	git config merge.tool bogus-tool &&
+	git config diff.tool test-tool &&
+
+	diff=$(git difftool --no-prompt branch) &&
+	test "$diff" = "branch" &&
+
+	restore_test_defaults
+'
+
+test_expect_success 'difftool.<tool>.path' '
+	git config difftool.tkdiff.path echo &&
+	diff=$(git difftool --no-prompt -t tkdiff branch) &&
+	git config --unset difftool.tkdiff.path &&
+	lines=$(echo "$diff" | grep file | wc -l) &&
+	test "$lines" = 1
+'
+
+test_done
-- 
1.6.2.2.414.g81aa9

[PATCH 11/14] difftool: add support for a difftool.prompt config variable

[David Aguilar]

difftool now supports difftool.prompt so that users do not have to
pass --no-prompt or hit enter each time a diff tool is launched.
The --prompt flag overrides the configuration variable.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 Documentation/config.txt       |    3 ++
 Documentation/git-difftool.txt |   10 +++++-
 git-difftool--helper.sh        |   10 +++++-
 git-difftool.perl              |   15 +++++++--
 t/t7800-difftool.sh            |   64 ++++++++++++++++++++++++++++++++++++++++
 5 files changed, 96 insertions(+), 6 deletions(-)

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 185a9ef..79c8b66 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -684,6 +684,9 @@ difftool.<tool>.cmd::
 	is set to the name of the temporary file containing the contents
 	of the diff post-image.
 
+difftool.prompt::
+	Prompt before each invocation of the diff tool.
+
 diff.wordRegex::
 	A POSIX Extended Regular Expression used to determine what is a "word"
 	when performing word-by-word difference calculations.  Character
diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index a2fa474..d2d762c 100644
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -7,7 +7,7 @@ git-difftool - Show changes using common diff tools
 
 SYNOPSIS
 --------
-'git difftool' [-t|--tool=<tool>] [-y|--no-prompt] [<'git diff' options>]
+'git difftool' [-t|--tool=<tool>] [-y|--no-prompt|--prompt] [<'git diff' options>]
 
 DESCRIPTION
 -----------
@@ -21,6 +21,11 @@ OPTIONS
 --no-prompt::
 	Do not prompt before launching a diff tool.
 
+--prompt::
+	Prompt before each invocation of the diff tool.
+	This is the default behaviour; the option is provided to
+	override any configuration settings.
+
 -t <tool>::
 --tool=<tool>::
 	Use the diff tool specified by <tool>.
@@ -72,6 +77,9 @@ difftool.<tool>.cmd::
 +
 See the `--tool=<tool>` option above for more details.
 
+difftool.prompt::
+	Prompt before each invocation of the diff tool.
+
 SEE ALSO
 --------
 linkgit:git-diff[1]::
diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
index fc61416..f3c27d8 100755
--- a/git-difftool--helper.sh
+++ b/git-difftool--helper.sh
@@ -5,9 +5,15 @@
 #
 # Copyright (c) 2009 David Aguilar
 
-# Set GIT_DIFFTOOL_NO_PROMPT to bypass the per-file prompt.
+# difftool.prompt controls the default prompt/no-prompt behavior
+# and is overridden with $GIT_DIFFTOOL*_PROMPT.
 should_prompt () {
-	test -z "$GIT_DIFFTOOL_NO_PROMPT"
+	prompt=$(git config --bool difftool.prompt || echo true)
+	if test "$prompt" = true; then
+		test -z "$GIT_DIFFTOOL_NO_PROMPT"
+	else
+		test -n "$GIT_DIFFTOOL_PROMPT"
+	fi
 }
 
 # This function prepares temporary files and launches the appropriate
diff --git a/git-difftool.perl b/git-difftool.perl
index 8857ac8..948ff7f 100755
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -2,9 +2,12 @@
 # Copyright (c) 2009 David Aguilar
 #
 # This is a wrapper around the GIT_EXTERNAL_DIFF-compatible
-# git-difftool--helper script.  This script exports
-# GIT_EXTERNAL_DIFF and GIT_PAGER for use by git, and
-# GIT_DIFFTOOL_NO_PROMPT and GIT_DIFF_TOOL for use by git-difftool--helper.
+# git-difftool--helper script.
+#
+# This script exports GIT_EXTERNAL_DIFF and GIT_PAGER for use by git.
+# GIT_DIFFTOOL_NO_PROMPT, GIT_DIFFTOOL_PROMPT, and GIT_DIFF_TOOL
+# are exported for use by git-difftool--helper.
+#
 # Any arguments that are unknown to this script are forwarded to 'git diff'.
 
 use strict;
@@ -62,6 +65,12 @@ sub generate_command
 		}
 		if ($arg eq '-y' || $arg eq '--no-prompt') {
 			$ENV{GIT_DIFFTOOL_NO_PROMPT} = 'true';
+			delete $ENV{GIT_DIFFTOOL_PROMPT};
+			next;
+		}
+		if ($arg eq '--prompt') {
+			$ENV{GIT_DIFFTOOL_PROMPT} = 'true';
+			delete $ENV{GIT_DIFFTOOL_NO_PROMPT};
 			next;
 		}
 		if ($arg eq '-h' || $arg eq '--help') {
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 85946d9..0b263ea 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -15,6 +15,7 @@ remove_config_vars()
 	# Unset all config variables used by git-difftool
 	git config --unset diff.tool
 	git config --unset difftool.test-tool.cmd
+	git config --unset difftool.prompt
 	git config --unset merge.tool
 	git config --unset mergetool.test-tool.cmd
 	return 0
@@ -26,11 +27,18 @@ restore_test_defaults()
 	remove_config_vars
 	unset GIT_DIFF_TOOL
 	unset GIT_MERGE_TOOL
+	unset GIT_DIFFTOOL_PROMPT
 	unset GIT_DIFFTOOL_NO_PROMPT
 	git config diff.tool test-tool &&
 	git config difftool.test-tool.cmd 'cat $LOCAL'
 }
 
+prompt_given()
+{
+	prompt="$1"
+	test "$prompt" = "Hit return to launch 'test-tool': branch"
+}
+
 # Create a file on master and change it on branch
 test_expect_success 'setup' '
 	echo master >file &&
@@ -116,6 +124,62 @@ test_expect_success 'GIT_DIFFTOOL_NO_PROMPT variable' '
 	restore_test_defaults
 '
 
+# git-difftool supports the difftool.prompt variable.
+# Test that GIT_DIFFTOOL_PROMPT can override difftool.prompt = false
+test_expect_success 'GIT_DIFFTOOL_PROMPT variable' '
+	git config difftool.prompt false &&
+	GIT_DIFFTOOL_PROMPT=true &&
+	export GIT_DIFFTOOL_PROMPT &&
+
+	prompt=$(echo | git difftool --prompt branch | tail -1) &&
+	prompt_given "$prompt" &&
+
+	restore_test_defaults
+'
+
+# Test that we don't have to pass --no-prompt when difftool.prompt is false
+test_expect_success 'difftool.prompt config variable is false' '
+	git config difftool.prompt false &&
+
+	diff=$(git difftool branch) &&
+	test "$diff" = "branch" &&
+
+	restore_test_defaults
+'
+
+# Test that the -y flag can override difftool.prompt = true
+test_expect_success 'difftool.prompt can overridden with -y' '
+	git config difftool.prompt true &&
+
+	diff=$(git difftool -y branch) &&
+	test "$diff" = "branch" &&
+
+	restore_test_defaults
+'
+
+# Test that the --prompt flag can override difftool.prompt = false
+test_expect_success 'difftool.prompt can overridden with --prompt' '
+	git config difftool.prompt false &&
+
+	prompt=$(echo | git difftool --prompt branch | tail -1) &&
+	prompt_given "$prompt" &&
+
+	restore_test_defaults
+'
+
+# Test that the last flag passed on the command-line wins
+test_expect_success 'difftool last flag wins' '
+	diff=$(git difftool --prompt --no-prompt branch) &&
+	test "$diff" = "branch" &&
+
+	restore_test_defaults &&
+
+	prompt=$(echo | git difftool --no-prompt --prompt branch | tail -1) &&
+	prompt_given "$prompt" &&
+
+	restore_test_defaults
+'
+
 # git-difftool falls back to git-mergetool config variables
 # so test that behavior here
 test_expect_success 'difftool + mergetool config variables' '
-- 
1.6.2.2.414.g81aa9

[PATCH 12/14] bash completion: add git-difftool

[David Aguilar]

This adds completion for difftool's --tool flag.
The known diff tool names were also consolidated into
a single variable.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 contrib/completion/git-completion.bash |   27 ++++++++++++++++++++++-----
 1 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 4fcd77a..551e33e 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -909,6 +909,26 @@ _git_diff ()
 	__git_complete_file
 }
 
+__git_mergetools_common="diffuse ecmerge emerge kdiff3 meld opendiff
+			tkdiff vimdiff gvimdiff xxdiff
+"
+
+_git_difftool ()
+{
+	local cur="${COMP_WORDS[COMP_CWORD]}"
+	case "$cur" in
+	--tool=*)
+		__gitcomp "$__git_mergetools_common kompare" "" "${cur##--tool=}"
+		return
+		;;
+	--*)
+		__gitcomp "--tool="
+		return
+		;;
+	esac
+	COMPREPLY=()
+}
+
 __git_fetch_options="
 	--quiet --verbose --append --upload-pack --force --keep --depth=
 	--tags --no-tags
@@ -1171,11 +1191,7 @@ _git_mergetool ()
 	local cur="${COMP_WORDS[COMP_CWORD]}"
 	case "$cur" in
 	--tool=*)
-		__gitcomp "
-			kdiff3 tkdiff meld xxdiff emerge
-			vimdiff gvimdiff ecmerge diffuse
-			opendiff
-			" "" "${cur##--tool=}"
+		__gitcomp "$__git_mergetools_common tortoisemerge" "" "${cur##--tool=}"
 		return
 		;;
 	--*)
@@ -1900,6 +1916,7 @@ _git ()
 	config)      _git_config ;;
 	describe)    _git_describe ;;
 	diff)        _git_diff ;;
+	difftool)    _git_difftool ;;
 	fetch)       _git_fetch ;;
 	format-patch) _git_format_patch ;;
 	fsck)        _git_fsck ;;
-- 
1.6.2.2.414.g81aa9

[PATCH 13/14] mergetool: use $( ... ) instead of `backticks`

[David Aguilar]

This makes mergetool consistent with Documentation/CodingGuidelines.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 git-mergetool.sh |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/git-mergetool.sh b/git-mergetool.sh
index b4d2432..cceebb7 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -137,7 +137,7 @@ checkout_staged_file () {
 merge_file () {
     MERGED="$1"
 
-    f=`git ls-files -u -- "$MERGED"`
+    f=$(git ls-files -u -- "$MERGED")
     if test -z "$f" ; then
 	if test ! -f "$MERGED" ; then
 	    echo "$MERGED: file not found"
@@ -156,9 +156,9 @@ merge_file () {
     mv -- "$MERGED" "$BACKUP"
     cp -- "$BACKUP" "$MERGED"
 
-    base_mode=`git ls-files -u -- "$MERGED" | awk '{if ($3==1) print $1;}'`
-    local_mode=`git ls-files -u -- "$MERGED" | awk '{if ($3==2) print $1;}'`
-    remote_mode=`git ls-files -u -- "$MERGED" | awk '{if ($3==3) print $1;}'`
+    base_mode=$(git ls-files -u -- "$MERGED" | awk '{if ($3==1) print $1;}')
+    local_mode=$(git ls-files -u -- "$MERGED" | awk '{if ($3==2) print $1;}')
+    remote_mode=$(git ls-files -u -- "$MERGED" | awk '{if ($3==3) print $1;}')
 
     base_present   && checkout_staged_file 1 "$MERGED" "$BASE"
     local_present  && checkout_staged_file 2 "$MERGED" "$LOCAL"
@@ -318,7 +318,7 @@ do
 	-t|--tool*)
 	    case "$#,$1" in
 		*,*=*)
-		    merge_tool=`expr "z$1" : 'z-[^=]*=\(.*\)'`
+		    merge_tool=$(expr "z$1" : 'z-[^=]*=\(.*\)')
 		    ;;
 		1,*)
 		    usage ;;
@@ -366,7 +366,7 @@ valid_tool() {
 }
 
 init_merge_tool_path() {
-	merge_tool_path=`git config mergetool.$1.path`
+	merge_tool_path=$(git config mergetool.$1.path)
 	if test -z "$merge_tool_path" ; then
 		case "$1" in
 			vimdiff)
@@ -403,7 +403,7 @@ prompt_after_failed_merge() {
 }
 
 if test -z "$merge_tool"; then
-    merge_tool=`git config merge.tool`
+    merge_tool=$(git config merge.tool)
     if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
 	    echo >&2 "git config option merge.tool set to unknown tool: $merge_tool"
 	    echo >&2 "Resetting to default..."
@@ -463,7 +463,7 @@ last_status=0
 rollup_status=0
 
 if test $# -eq 0 ; then
-    files=`git ls-files -u | sed -e 's/^[^	]*	//' | sort -u`
+    files=$(git ls-files -u | sed -e 's/^[^	]*	//' | sort -u)
     if test -z "$files" ; then
 	echo "No files need merging"
 	exit 0
-- 
1.6.2.2.414.g81aa9

[PATCH 14/14] difftool/mergetool: refactor commands to use git-mergetool--lib

[David Aguilar]

This consolidates the common functionality from git-mergetool and
git-difftool--helper into a single git-mergetool--lib scriptlet.

Signed-off-by: David Aguilar <davvid@gmail.com>
---
 .gitignore                           |    1 +
 Documentation/git-mergetool--lib.txt |   56 ++++++
 Makefile                             |    1 +
 git-difftool--helper.sh              |  186 +-----------------
 git-mergetool--lib.sh                |  346 ++++++++++++++++++++++++++++++++++
 git-mergetool.sh                     |  224 ++---------------------
 6 files changed, 426 insertions(+), 388 deletions(-)
 create mode 100644 Documentation/git-mergetool--lib.txt
 create mode 100644 git-mergetool--lib.sh

diff --git a/.gitignore b/.gitignore
index a36da9d..757c7f0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -80,6 +80,7 @@ git-merge-recursive
 git-merge-resolve
 git-merge-subtree
 git-mergetool
+git-mergetool--lib
 git-mktag
 git-mktree
 git-name-rev
diff --git a/Documentation/git-mergetool--lib.txt b/Documentation/git-mergetool--lib.txt
new file mode 100644
index 0000000..3d57031
--- /dev/null
+++ b/Documentation/git-mergetool--lib.txt
@@ -0,0 +1,56 @@
+git-mergetool--lib(1)
+=====================
+
+NAME
+----
+git-mergetool--lib - Common git merge tool shell scriptlets
+
+SYNOPSIS
+--------
+'. "$(git --exec-path)/git-mergetool--lib"'
+
+DESCRIPTION
+-----------
+
+This is not a command the end user would want to run.  Ever.
+This documentation is meant for people who are studying the
+Porcelain-ish scripts and/or are writing new ones.
+
+The 'git-mergetool--lib' scriptlet is designed to be sourced (using
+`.`) by other shell scripts to set up functions for working
+with git merge tools.
+
+Before sourcing it, your script should set up a few variables;
+`TOOL_MODE` is used to define the operation mode for various
+functions.  'diff' and 'merge' are valid values.
+
+FUNCTIONS
+---------
+get_merge_tool::
+	returns a merge tool
+
+get_merge_tool_cmd::
+	returns the custom command for a merge tool.
+
+get_merge_tool_path::
+	returns the custom path for a merge tool.
+
+run_merge_tool::
+	launches a merge tool given the tool name and a true/false
+	flag to indicate whether a merge base is present.
+	'$merge_tool', '$merge_tool_path', and for custom commands,
+	'$merge_tool_cmd', must be defined prior to calling
+	run_merge_tool.  Additionally, '$MERGED', '$LOCAL', '$REMOTE',
+	and '$BASE' must be defined for use by the merge tool.
+
+Author
+------
+Written by David Aguilar <davvid@gmail.com>
+
+Documentation
+--------------
+Documentation by David Aguilar and the git-list <git@vger.kernel.org>.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/Makefile b/Makefile
index a80055f..3e56274 100644
--- a/Makefile
+++ b/Makefile
@@ -284,6 +284,7 @@ SCRIPT_SH += git-merge-octopus.sh
 SCRIPT_SH += git-merge-one-file.sh
 SCRIPT_SH += git-merge-resolve.sh
 SCRIPT_SH += git-mergetool.sh
+SCRIPT_SH += git-mergetool--lib.sh
 SCRIPT_SH += git-parse-remote.sh
 SCRIPT_SH += git-pull.sh
 SCRIPT_SH += git-quiltimport.sh
diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
index f3c27d8..b450036 100755
--- a/git-difftool--helper.sh
+++ b/git-difftool--helper.sh
@@ -5,6 +5,10 @@
 #
 # Copyright (c) 2009 David Aguilar
 
+# Load common functions from git-mergetool--lib
+TOOL_MODE=diff
+. git-mergetool--lib
+
 # difftool.prompt controls the default prompt/no-prompt behavior
 # and is overridden with $GIT_DIFFTOOL*_PROMPT.
 should_prompt () {
@@ -16,8 +20,7 @@ should_prompt () {
 	fi
 }
 
-# This function prepares temporary files and launches the appropriate
-# merge tool.
+# Sets up shell variables and runs a merge tool
 launch_merge_tool () {
 	# Merged is the filename as it appears in the work tree
 	# Local is the contents of a/filename
@@ -37,187 +40,16 @@ launch_merge_tool () {
 	fi
 
 	# Run the appropriate merge tool command
-	case "$merge_tool" in
-	kdiff3)
-		basename=$(basename "$MERGED")
-		"$merge_tool_path" --auto \
-			--L1 "$basename (A)" \
-			--L2 "$basename (B)" \
-			"$LOCAL" "$REMOTE" \
-			> /dev/null 2>&1
-		;;
-
-	kompare)
-		"$merge_tool_path" "$LOCAL" "$REMOTE"
-		;;
-
-	tkdiff)
-		"$merge_tool_path" "$LOCAL" "$REMOTE"
-		;;
-
-	meld)
-		"$merge_tool_path" "$LOCAL" "$REMOTE"
-		;;
-
-	diffuse)
-		"$merge_tool_path" "$LOCAL" "$REMOTE" | cat
-		;;
-
-	vimdiff)
-		"$merge_tool_path" -d -c "wincmd l" "$LOCAL" "$REMOTE"
-		;;
-
-	gvimdiff)
-		"$merge_tool_path" -d -c "wincmd l" -f "$LOCAL" "$REMOTE"
-		;;
-
-	xxdiff)
-		"$merge_tool_path" \
-			-R 'Accel.Search: "Ctrl+F"' \
-			-R 'Accel.SearchForward: "Ctrl-G"' \
-			"$LOCAL" "$REMOTE"
-		;;
-
-	opendiff)
-		"$merge_tool_path" "$LOCAL" "$REMOTE" | cat
-		;;
-
-	ecmerge)
-		"$merge_tool_path" "$LOCAL" "$REMOTE" \
-			--default --mode=merge2 --to="$MERGED"
-		;;
-
-	emerge)
-		"$merge_tool_path" -f emerge-files-command \
-			"$LOCAL" "$REMOTE" "$(basename "$MERGED")"
-		;;
-
-	*)
-		if test -n "$merge_tool_cmd"; then
-			( eval $merge_tool_cmd )
-		fi
-		;;
-	esac
-}
-
-# Verifies that (difftool|mergetool).<tool>.cmd exists
-valid_custom_tool() {
-	merge_tool_cmd="$(git config difftool.$1.cmd)"
-	test -z "$merge_tool_cmd" &&
-	merge_tool_cmd="$(git config mergetool.$1.cmd)"
-	test -n "$merge_tool_cmd"
-}
-
-# Verifies that the chosen merge tool is properly setup.
-# Built-in merge tools are always valid.
-valid_tool() {
-	case "$1" in
-	kdiff3 | kompare | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge)
-		;; # happy
-	*)
-		if ! valid_custom_tool "$1"
-		then
-			return 1
-		fi
-		;;
-	esac
-}
-
-# Sets up the merge_tool_path variable.
-# This handles the difftool.<tool>.path configuration.
-# This also falls back to mergetool defaults.
-init_merge_tool_path() {
-	merge_tool_path=$(git config difftool."$1".path)
-	test -z "$merge_tool_path" &&
-	merge_tool_path=$(git config mergetool."$1".path)
-	if test -z "$merge_tool_path"; then
-		case "$1" in
-		vimdiff)
-			merge_tool_path=vim
-			;;
-		gvimdiff)
-			merge_tool_path=gvim
-			;;
-		emerge)
-			merge_tool_path=emacs
-			;;
-		*)
-			merge_tool_path="$1"
-			;;
-		esac
-	fi
+	run_merge_tool "$merge_tool"
 }
 
 # Allow GIT_DIFF_TOOL and GIT_MERGE_TOOL to provide default values
 test -n "$GIT_MERGE_TOOL" && merge_tool="$GIT_MERGE_TOOL"
 test -n "$GIT_DIFF_TOOL" && merge_tool="$GIT_DIFF_TOOL"
 
-# If merge tool was not specified then use the diff.tool
-# configuration variable.  If that's invalid then reset merge_tool.
-# Fallback to merge.tool.
-if test -z "$merge_tool"; then
-	merge_tool=$(git config diff.tool)
-	test -z "$merge_tool" &&
-	merge_tool=$(git config merge.tool)
-	if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
-		echo >&2 "git config option diff.tool set to unknown tool: $merge_tool"
-		echo >&2 "Resetting to default..."
-		unset merge_tool
-	fi
-fi
-
-# Try to guess an appropriate merge tool if no tool has been set.
-if test -z "$merge_tool"; then
-	# We have a $DISPLAY so try some common UNIX merge tools
-	if test -n "$DISPLAY"; then
-		# If gnome then prefer meld, otherwise, prefer kdiff3 or kompare
-		if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
-			merge_tool_candidates="meld kdiff3 kompare tkdiff xxdiff gvimdiff diffuse"
-		else
-			merge_tool_candidates="kdiff3 kompare tkdiff xxdiff meld gvimdiff diffuse"
-		fi
-	fi
-	if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then
-		# $EDITOR is emacs so add emerge as a candidate
-		merge_tool_candidates="$merge_tool_candidates emerge opendiff vimdiff"
-	elif echo "${VISUAL:-$EDITOR}" | grep 'vim' > /dev/null 2>&1; then
-		# $EDITOR is vim so add vimdiff as a candidate
-		merge_tool_candidates="$merge_tool_candidates vimdiff opendiff emerge"
-	else
-		merge_tool_candidates="$merge_tool_candidates opendiff emerge vimdiff"
-	fi
-	echo "merge tool candidates: $merge_tool_candidates"
-
-	# Loop over each candidate and stop when a valid merge tool is found.
-	for i in $merge_tool_candidates
-	do
-		init_merge_tool_path $i
-		if type "$merge_tool_path" > /dev/null 2>&1; then
-			merge_tool=$i
-			break
-		fi
-	done
-
-	if test -z "$merge_tool" ; then
-		echo "No known merge resolution program available."
-		exit 1
-	fi
-
-else
-	# A merge tool has been set, so verify that it's valid.
-	if ! valid_tool "$merge_tool"; then
-		echo >&2 "Unknown merge tool $merge_tool"
-		exit 1
-	fi
-
-	init_merge_tool_path "$merge_tool"
-
-	if test -z "$merge_tool_cmd" && ! type "$merge_tool_path" > /dev/null 2>&1; then
-		echo "The merge tool $merge_tool is not available as '$merge_tool_path'"
-		exit 1
-	fi
-fi
-
+merge_tool=$(get_merge_tool "$merge_tool") || exit
+merge_tool_cmd="$(get_merge_tool_cmd "$merge_tool")"
+merge_tool_path="$(get_merge_tool_path "$merge_tool")" || exit
 
 # Launch the merge tool on each path provided by 'git diff'
 while test $# -gt 6
diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
new file mode 100644
index 0000000..fa1d0ff
--- /dev/null
+++ b/git-mergetool--lib.sh
@@ -0,0 +1,346 @@
+# git-mergetool--lib is a library for common merge tool functions
+diff_mode() {
+	test $TOOL_MODE = "diff"
+}
+
+merge_mode() {
+	test $TOOL_MODE = "merge"
+}
+
+translate_merge_tool_path () {
+	if test -n "$2"; then
+		echo "$2"
+	else
+		case "$1" in
+		vimdiff)
+			path=vim
+			;;
+		gvimdiff)
+			path=gvim
+			;;
+		emerge)
+			path=emacs
+			;;
+		*)
+			path="$1"
+			;;
+		esac
+		echo "$path"
+	fi
+}
+
+check_unchanged () {
+	if merge_mode; then
+		if test "$MERGED" -nt "$BACKUP"; then
+			status=0
+		else
+			while true; do
+				echo "$MERGED seems unchanged."
+				printf "Was the merge successful? [y/n] "
+				read answer < /dev/tty
+				case "$answer" in
+				y*|Y*) status=0; break ;;
+				n*|N*) status=1; break ;;
+				esac
+			done
+		fi
+	else
+		status=0
+	fi
+	return $status
+}
+
+valid_tool () {
+	case "$1" in
+	kdiff3 | tkdiff | xxdiff | meld | opendiff | \
+	emerge | vimdiff | gvimdiff | ecmerge | diffuse)
+		return 0
+		;; # happy
+	esac
+	if merge_mode && test "$1" = tortoisemerge; then
+		return 0
+	fi
+	if diff_mode && test "$1" = kompare; then
+		return 0
+	fi
+	test -n "$(get_merge_tool_cmd "$1")"
+}
+
+get_merge_tool_cmd () {
+	diff_mode &&
+	custom_cmd="$(git config difftool.$1.cmd)"
+	test -z "$custom_cmd" &&
+	custom_cmd="$(git config mergetool.$1.cmd)"
+	test -n "$custom_cmd" &&
+	echo "$custom_cmd"
+}
+
+run_merge_tool () {
+	base_present="$2"
+	if diff_mode; then
+		base_present="false"
+	fi
+	if test -z "$base_present"; then
+		base_present="true"
+	fi
+
+	case "$1" in
+	kdiff3)
+		if $base_present; then
+			("$merge_tool_path" --auto \
+			 --L1 "$MERGED (Base)" --L2 "$MERGED (Local)" --L3 "$MERGED (Remote)" \
+			 -o "$MERGED" "$BASE" "$LOCAL" "$REMOTE" > /dev/null 2>&1)
+		else
+			if merge_mode; then
+				("$merge_tool_path" --auto \
+				 --L1 "$MERGED (Local)" \
+				 --L2 "$MERGED (Remote)" \
+				 -o "$MERGED" "$LOCAL" "$REMOTE" \
+				> /dev/null 2>&1)
+			else
+				("$merge_tool_path" --auto \
+				 --L1 "$MERGED (A)" \
+				 --L2 "$MERGED (B)" \
+				 "$LOCAL" "$REMOTE" \
+				> /dev/null 2>&1)
+			fi
+		fi
+		status=$?
+		;;
+	kompare)
+		"$merge_tool_path" "$LOCAL" "$REMOTE"
+		status=$?
+		;;
+	tkdiff)
+		if $base_present; then
+			"$merge_tool_path" -a "$BASE" -o "$MERGED" "$LOCAL" "$REMOTE"
+		else
+			if merge_mode; then
+				"$merge_tool_path" -o "$MERGED" "$LOCAL" "$REMOTE"
+			else
+				"$merge_tool_path" "$LOCAL" "$REMOTE"
+			fi
+		fi
+		status=$?
+		;;
+	meld)
+		if merge_mode; then
+			touch "$BACKUP"
+			"$merge_tool_path" "$LOCAL" "$MERGED" "$REMOTE"
+		else
+			"$merge_tool_path" "$LOCAL" "$REMOTE"
+		fi
+		check_unchanged
+		;;
+	diffuse)
+		if merge_mode; then
+			touch "$BACKUP"
+		fi
+		if $base_present; then
+			"$merge_tool_path" "$LOCAL" "$MERGED" "$REMOTE" "$BASE" | cat
+		else
+			if merge_mode; then
+				"$merge_tool_path" "$LOCAL" "$MERGED" "$REMOTE" | cat
+			else
+				"$merge_tool_path" "$LOCAL" "$REMOTE" | cat
+			fi
+		fi
+		check_unchanged
+		;;
+	vimdiff)
+		if merge_mode; then
+			touch "$BACKUP"
+			"$merge_tool_path" -d -c "wincmd l" "$LOCAL" "$MERGED" "$REMOTE"
+			check_unchanged
+		else
+			"$merge_tool_path" -d -c "wincmd l" "$LOCAL" "$REMOTE"
+		fi
+		;;
+	gvimdiff)
+		if merge_mode; then
+			touch "$BACKUP"
+			"$merge_tool_path" -d -c "wincmd l" -f "$LOCAL" "$MERGED" "$REMOTE"
+			check_unchanged
+		else
+			"$merge_tool_path" -d -c "wincmd l" -f "$LOCAL" "$REMOTE"
+		fi
+		;;
+	xxdiff)
+		if merge_mode; then
+			touch "$BACKUP"
+		fi
+		if $base_present; then
+			"$merge_tool_path" -X --show-merged-pane \
+			    -R 'Accel.SaveAsMerged: "Ctrl-S"' \
+			    -R 'Accel.Search: "Ctrl+F"' \
+			    -R 'Accel.SearchForward: "Ctrl-G"' \
+			    --merged-file "$MERGED" "$LOCAL" "$BASE" "$REMOTE"
+		else
+			if merge_mode; then
+				"$merge_tool_path" -X $extra \
+					-R 'Accel.SaveAsMerged: "Ctrl-S"' \
+					-R 'Accel.Search: "Ctrl+F"' \
+					-R 'Accel.SearchForward: "Ctrl-G"' \
+					--merged-file "$MERGED" "$LOCAL" "$REMOTE"
+			else
+				"$merge_tool_path" \
+					-R 'Accel.Search: "Ctrl+F"' \
+					-R 'Accel.SearchForward: "Ctrl-G"' \
+					"$LOCAL" "$REMOTE"
+			fi
+		fi
+		check_unchanged
+		;;
+	opendiff)
+		merge_mode && touch "$BACKUP"
+		if $base_present; then
+			"$merge_tool_path" "$LOCAL" "$REMOTE" \
+				-ancestor "$BASE" -merge "$MERGED" | cat
+		else
+			if merge_mode; then
+				"$merge_tool_path" "$LOCAL" "$REMOTE" \
+					-merge "$MERGED" | cat
+			else
+				"$merge_tool_path" "$LOCAL" "$REMOTE" | cat
+			fi
+		fi
+		check_unchanged
+		;;
+	ecmerge)
+		merge_mode && touch "$BACKUP"
+		if $base_present; then
+			"$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" \
+				--default --mode=merge3 --to="$MERGED"
+		else
+			"$merge_tool_path" "$LOCAL" "$REMOTE" \
+				--default --mode=merge2 --to="$MERGED"
+		fi
+		check_unchanged
+		;;
+	emerge)
+		if $base_present; then
+			"$merge_tool_path" -f emerge-files-with-ancestor-command \
+				"$LOCAL" "$REMOTE" "$BASE" "$(basename "$MERGED")"
+		else
+			"$merge_tool_path" -f emerge-files-command \
+				"$LOCAL" "$REMOTE" "$(basename "$MERGED")"
+		fi
+		status=$?
+		;;
+	tortoisemerge)
+		if $base_present; then
+			touch "$BACKUP"
+			"$merge_tool_path" -base:"$BASE" -mine:"$LOCAL" -theirs:"$REMOTE" -merged:"$MERGED"
+			check_unchanged
+		else
+			echo "TortoiseMerge cannot be used without a base" 1>&2
+			status=1
+		fi
+		;;
+	*)
+		if test -n "$merge_tool_cmd"; then
+			if merge_mode &&
+			test "$merge_tool_trust_exit_code" = "false"; then
+				touch "$BACKUP"
+				( eval $merge_tool_cmd )
+				check_unchanged
+			else
+				( eval $merge_tool_cmd )
+				status=$?
+			fi
+		fi
+		;;
+	esac
+	return $status
+}
+
+guess_merge_tool () {
+	if diff_mode; then
+		kompare="kompare"
+	fi
+	if test -n "$DISPLAY"; then
+		if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
+			tools="meld kdiff3 $kompare tkdiff"
+			tools="$tools xxdiff gvimdiff diffuse"
+		else
+			tools="kdiff3 $kompare tkdiff xxdiff"
+			tools="$tools meld gvimdiff diffuse"
+		fi
+	fi
+	if echo "${VISUAL:-$EDITOR}" | grep emacs > /dev/null 2>&1; then
+		# $EDITOR is emacs so add emerge as a candidate
+		tools="$tools emerge opendiff vimdiff"
+	elif echo "${VISUAL:-$EDITOR}" | grep vim > /dev/null 2>&1; then
+		# $EDITOR is vim so add vimdiff as a candidate
+		tools="$tools vimdiff opendiff emerge"
+	else
+		tools="$tools opendiff emerge vimdiff"
+	fi
+	echo >&2 "merge tool candidates: $tools"
+
+	# Loop over each candidate and stop when a valid merge tool is found.
+	for i in $tools
+	do
+		merge_tool_path="$(translate_merge_tool_path "$i")"
+		if type "$merge_tool_path" > /dev/null 2>&1; then
+			merge_tool="$i"
+			break
+		fi
+	done
+
+	if test -z "$merge_tool" ; then
+		echo >&2 "No known merge resolution program available."
+		return 1
+	fi
+	echo "$merge_tool"
+}
+
+get_configured_merge_tool () {
+	# Diff mode first tries diff.tool and falls back to merge.tool.
+	# Merge mode only checks merge.tool
+	if diff_mode; then
+		tool=$(git config diff.tool)
+	fi
+	if test -z "$tool"; then
+		tool=$(git config merge.tool)
+	fi
+	if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
+		echo >&2 "git config option $TOOL_MODE.tool set to unknown tool: $merge_tool"
+		echo >&2 "Resetting to default..."
+		return 1
+	fi
+	echo "$tool"
+}
+
+get_merge_tool_path () {
+	# A merge tool has been set, so verify that it's valid.
+	if ! valid_tool "$merge_tool"; then
+		echo >&2 "Unknown merge tool $merge_tool"
+		exit 1
+	fi
+	if diff_mode; then
+		merge_tool_path=$(git config difftool."$merge_tool".path)
+	fi
+	if test -z "$merge_tool_path"; then
+		merge_tool_path=$(git config mergetool."$merge_tool".path)
+	fi
+	merge_tool_path="$(translate_merge_tool_path "$merge_tool" "$merge_tool_path")"
+	if test -z "$merge_tool_cmd" && ! type "$merge_tool_path" > /dev/null 2>&1; then
+		echo >&2 "The $TOOL_MODE tool $merge_tool is not available as '$merge_tool_path'"
+		exit 1
+	fi
+	echo "$merge_tool_path"
+}
+
+get_merge_tool () {
+	merge_tool="$1"
+	# Check if a merge tool has been configured
+	if test -z "$merge_tool"; then
+		merge_tool=$(get_configured_merge_tool)
+	fi
+	# Try to guess an appropriate merge tool if no tool has been set.
+	if test -z "$merge_tool"; then
+		merge_tool=$(guess_merge_tool) || exit
+	fi
+	echo "$merge_tool"
+}
diff --git a/git-mergetool.sh b/git-mergetool.sh
index cceebb7..efa31a2 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -11,7 +11,9 @@
 USAGE='[--tool=tool] [-y|--no-prompt|--prompt] [file to merge] ...'
 SUBDIRECTORY_OK=Yes
 OPTIONS_SPEC=
+TOOL_MODE=merge
 . git-sh-setup
+. git-mergetool--lib
 require_work_tree
 
 # Returns true if the mode reflects a symlink
@@ -110,22 +112,6 @@ resolve_deleted_merge () {
 	done
 }
 
-check_unchanged () {
-    if test "$MERGED" -nt "$BACKUP" ; then
-	status=0;
-    else
-	while true; do
-	    echo "$MERGED seems unchanged."
-	    printf "Was the merge successful? [y/n] "
-	    read answer < /dev/tty
-	    case "$answer" in
-		y*|Y*) status=0; break ;;
-		n*|N*) status=1; break ;;
-	    esac
-	done
-    fi
-}
-
 checkout_staged_file () {
     tmpfile=$(expr "$(git checkout-index --temp --stage="$1" "$2")" : '\([^	]*\)	')
 
@@ -188,107 +174,11 @@ merge_file () {
 	read ans
     fi
 
-    case "$merge_tool" in
-	kdiff3)
-	    if base_present ; then
-		("$merge_tool_path" --auto --L1 "$MERGED (Base)" --L2 "$MERGED (Local)" --L3 "$MERGED (Remote)" \
-		    -o "$MERGED" "$BASE" "$LOCAL" "$REMOTE" > /dev/null 2>&1)
-	    else
-		("$merge_tool_path" --auto --L1 "$MERGED (Local)" --L2 "$MERGED (Remote)" \
-		    -o "$MERGED" "$LOCAL" "$REMOTE" > /dev/null 2>&1)
-	    fi
-	    status=$?
-	    ;;
-	tkdiff)
-	    if base_present ; then
-		"$merge_tool_path" -a "$BASE" -o "$MERGED" "$LOCAL" "$REMOTE"
-	    else
-		"$merge_tool_path" -o "$MERGED" "$LOCAL" "$REMOTE"
-	    fi
-	    status=$?
-	    ;;
-	meld)
-	    touch "$BACKUP"
-	    "$merge_tool_path" "$LOCAL" "$MERGED" "$REMOTE"
-	    check_unchanged
-	    ;;
-	vimdiff)
-	    touch "$BACKUP"
-	    "$merge_tool_path" -d -c "wincmd l" "$LOCAL" "$MERGED" "$REMOTE"
-	    check_unchanged
-	    ;;
-	gvimdiff)
-	    touch "$BACKUP"
-	    "$merge_tool_path" -d -c "wincmd l" -f "$LOCAL" "$MERGED" "$REMOTE"
-	    check_unchanged
-	    ;;
-	xxdiff)
-	    touch "$BACKUP"
-	    if base_present ; then
-		"$merge_tool_path" -X --show-merged-pane \
-		    -R 'Accel.SaveAsMerged: "Ctrl-S"' \
-		    -R 'Accel.Search: "Ctrl+F"' \
-		    -R 'Accel.SearchForward: "Ctrl-G"' \
-		    --merged-file "$MERGED" "$LOCAL" "$BASE" "$REMOTE"
-	    else
-		"$merge_tool_path" -X --show-merged-pane \
-		    -R 'Accel.SaveAsMerged: "Ctrl-S"' \
-		    -R 'Accel.Search: "Ctrl+F"' \
-		    -R 'Accel.SearchForward: "Ctrl-G"' \
-		    --merged-file "$MERGED" "$LOCAL" "$REMOTE"
-	    fi
-	    check_unchanged
-	    ;;
-	opendiff)
-	    touch "$BACKUP"
-	    if base_present; then
-		"$merge_tool_path" "$LOCAL" "$REMOTE" -ancestor "$BASE" -merge "$MERGED" | cat
-	    else
-		"$merge_tool_path" "$LOCAL" "$REMOTE" -merge "$MERGED" | cat
-	    fi
-	    check_unchanged
-	    ;;
-	ecmerge)
-	    touch "$BACKUP"
-	    if base_present; then
-		"$merge_tool_path" "$BASE" "$LOCAL" "$REMOTE" --default --mode=merge3 --to="$MERGED"
-	    else
-		"$merge_tool_path" "$LOCAL" "$REMOTE" --default --mode=merge2 --to="$MERGED"
-	    fi
-	    check_unchanged
-	    ;;
-	emerge)
-	    if base_present ; then
-		"$merge_tool_path" -f emerge-files-with-ancestor-command "$LOCAL" "$REMOTE" "$BASE" "$(basename "$MERGED")"
-	    else
-		"$merge_tool_path" -f emerge-files-command "$LOCAL" "$REMOTE" "$(basename "$MERGED")"
-	    fi
-	    status=$?
-	    ;;
-	tortoisemerge)
-	    if base_present ; then
-		touch "$BACKUP"
-		"$merge_tool_path" -base:"$BASE" -mine:"$LOCAL" -theirs:"$REMOTE" -merged:"$MERGED"
-		check_unchanged
-	    else
-		echo "TortoiseMerge cannot be used without a base" 1>&2
-		status=1
-	    fi
-	    ;;
-	*)
-	    if test -n "$merge_tool_cmd"; then
-		if test "$merge_tool_trust_exit_code" = "false"; then
-		    touch "$BACKUP"
-		    ( eval $merge_tool_cmd )
-		    check_unchanged
-		else
-		    ( eval $merge_tool_cmd )
-		    status=$?
-		fi
-	    fi
-	    ;;
-    esac
-    if test "$status" -ne 0; then
+    present=false
+    base_present &&
+    present=true
+
+    if ! run_merge_tool "$merge_tool" "$present"; then
 	echo "merge of $MERGED failed" 1>&2
 	mv -- "$BACKUP" "$MERGED"
 
@@ -347,44 +237,6 @@ do
     shift
 done
 
-valid_custom_tool()
-{
-    merge_tool_cmd="$(git config mergetool.$1.cmd)"
-    test -n "$merge_tool_cmd"
-}
-
-valid_tool() {
-	case "$1" in
-		kdiff3 | tkdiff | xxdiff | meld | opendiff | emerge | vimdiff | gvimdiff | ecmerge | tortoisemerge)
-			;; # happy
-		*)
-			if ! valid_custom_tool "$1"; then
-				return 1
-			fi
-			;;
-	esac
-}
-
-init_merge_tool_path() {
-	merge_tool_path=$(git config mergetool.$1.path)
-	if test -z "$merge_tool_path" ; then
-		case "$1" in
-			vimdiff)
-				merge_tool_path=vim
-				;;
-			gvimdiff)
-				merge_tool_path=gvim
-				;;
-			emerge)
-				merge_tool_path=emacs
-				;;
-			*)
-				merge_tool_path=$1
-				;;
-		esac
-	fi
-}
-
 prompt_after_failed_merge() {
     while true; do
 	printf "Continue merging other unresolved paths (y/n) ? "
@@ -402,62 +254,12 @@ prompt_after_failed_merge() {
     done
 }
 
-if test -z "$merge_tool"; then
-    merge_tool=$(git config merge.tool)
-    if test -n "$merge_tool" && ! valid_tool "$merge_tool"; then
-	    echo >&2 "git config option merge.tool set to unknown tool: $merge_tool"
-	    echo >&2 "Resetting to default..."
-	    unset merge_tool
-    fi
-fi
-
-if test -z "$merge_tool" ; then
-    if test -n "$DISPLAY"; then
-        if test -n "$GNOME_DESKTOP_SESSION_ID" ; then
-            merge_tool_candidates="meld kdiff3 tkdiff xxdiff tortoisemerge gvimdiff diffuse"
-        else
-            merge_tool_candidates="kdiff3 tkdiff xxdiff meld tortoisemerge gvimdiff diffuse"
-        fi
-    fi
-    if echo "${VISUAL:-$EDITOR}" | grep 'emacs' > /dev/null 2>&1; then
-        merge_tool_candidates="$merge_tool_candidates emerge opendiff vimdiff"
-    elif echo "${VISUAL:-$EDITOR}" | grep 'vim' > /dev/null 2>&1; then
-        merge_tool_candidates="$merge_tool_candidates vimdiff opendiff emerge"
-    else
-        merge_tool_candidates="$merge_tool_candidates opendiff emerge vimdiff"
-    fi
-    echo "merge tool candidates: $merge_tool_candidates"
-    for i in $merge_tool_candidates; do
-        init_merge_tool_path $i
-        if type "$merge_tool_path" > /dev/null 2>&1; then
-            merge_tool=$i
-            break
-        fi
-    done
-    if test -z "$merge_tool" ; then
-	echo "No known merge resolution program available."
-	exit 1
-    fi
-else
-    if ! valid_tool "$merge_tool"; then
-        echo >&2 "Unknown merge_tool $merge_tool"
-        exit 1
-    fi
-
-    init_merge_tool_path "$merge_tool"
-
-    merge_keep_backup="$(git config --bool merge.keepBackup || echo true)"
-    merge_keep_temporaries="$(git config --bool mergetool.keepTemporaries || echo false)"
-
-    if test -z "$merge_tool_cmd" && ! type "$merge_tool_path" > /dev/null 2>&1; then
-        echo "The merge tool $merge_tool is not available as '$merge_tool_path'"
-        exit 1
-    fi
-
-    if ! test -z "$merge_tool_cmd"; then
-        merge_tool_trust_exit_code="$(git config --bool mergetool.$merge_tool.trustExitCode || echo false)"
-    fi
-fi
+merge_tool=$(get_merge_tool "$merge_tool") || exit
+merge_tool_cmd="$(get_merge_tool_cmd "$merge_tool")"
+merge_tool_path="$(get_merge_tool_path "$merge_tool")" || exit
+merge_keep_backup="$(git config --bool merge.keepBackup || echo true)"
+merge_keep_temporaries="$(git config --bool mergetool.keepTemporaries || echo false)"
+merge_tool_trust_exit_code="$(git config --bool mergetool."$merge_tool".trustExitCode || echo false)"
 
 last_status=0
 rollup_status=0
-- 
1.6.2.2.414.g81aa9

Re: [PATCH 07/14] difftool: add a -y shortcut for --no-prompt

[Markus Heidelberg]

David Aguilar, 06.04.2009:
> diff --git a/contrib/difftool/git-difftool.txt b/contrib/difftool/git-difftool.txt
> index 2b7bc03..4dff529 100644
> --- a/contrib/difftool/git-difftool.txt
> +++ b/contrib/difftool/git-difftool.txt
> @@ -3,35 +3,32 @@ git-difftool(1)
>  
>  NAME
>  ----
> -git-difftool - compare changes using common merge tools
> +git-difftool - Show changes using common diff tools
>  
>  SYNOPSIS
>  --------
> -'git difftool' [--tool=<tool>] [--no-prompt] ['git diff' options]
> +'git difftool' [-t|--tool=<tool>] [-y|--no-prompt] [<'git diff' options>]

"-t <tool>" would be more correct than only "-t". But I'm not sure if it
should go in there, mergetool doesn't have it either. It's only the
synopsis, is there any "official" guideline on how much to include
there and whether to avoid different options with the same meaning?

Re: [PATCH 09/14] difftool: move 'git-difftool' out of contrib

[Markus Heidelberg]

David Aguilar, 06.04.2009:
> diff --git a/Documentation/config.txt b/Documentation/config.txt
> +diff.tool::
> +	Controls which diff tool is used.  `diff.tool` overrides
> +	`merge.tool` when used by linkgit:git-difftool[1] and has
> +	the same valid values as `merge.tool`.

+kompare
-tortoisemerge