[PATCH 1/3] Add --gui option to mergetool

[Denton Liu <liu.denton@gmail.com>]

This fixes the discrepancy between difftool and mergetool where the
former has the --gui flag and the latter does not by adding the
functionality to mergetool.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
 Documentation/git-mergetool.txt        |  8 +++++++-
 contrib/completion/git-completion.bash |  3 ++-
 git-mergetool.sh                       |  5 ++++-
 t/t7610-mergetool.sh                   | 28 +++++++++++++++++++++++++++-
 4 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-mergetool.txt b/Documentation/git-mergetool.txt
index 3622d6648..2ab56efcf 100644
--- a/Documentation/git-mergetool.txt
+++ b/Documentation/git-mergetool.txt
@@ -8,7 +8,7 @@ git-mergetool - Run merge conflict resolution tools to resolve merge conflicts
 SYNOPSIS
 --------
 [verse]
-'git mergetool' [--tool=<tool>] [-y | --[no-]prompt] [<file>...]
+'git mergetool' [--tool=<tool>] [-g|--gui] [-y | --[no-]prompt] [<file>...]
 
 DESCRIPTION
 -----------
@@ -64,6 +64,12 @@ variable `mergetool.<tool>.trustExitCode` can be set to `true`.
 Otherwise, 'git mergetool' will prompt the user to indicate the
 success of the resolution after the custom tool has exited.
 
+-g::
+--gui::
+	When 'git-mergetool' is invoked with the `-g` or `--gui` option
+	the default diff tool will be read from the configured
+	`merge.guitool` variable instead of `merge.tool`.
+
 --tool-help::
 	Print a list of merge tools that may be used with `--tool`.
 
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 41ee52991..d5f3b9aeb 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -1584,7 +1584,7 @@ _git_mergetool ()
 		return
 		;;
 	--*)
-		__gitcomp "--tool= --prompt --no-prompt"
+		__gitcomp "--tool= --prompt --no-prompt --gui"
 		return
 		;;
 	esac
@@ -2308,6 +2308,7 @@ _git_config ()
 		merge.renormalize
 		merge.stat
 		merge.tool
+		merge.guitool
 		merge.verbosity
 		mergetool.
 		mergetool.keepBackup
diff --git a/git-mergetool.sh b/git-mergetool.sh
index c062e3de3..f3fce528b 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -9,7 +9,7 @@
 # at the discretion of Junio C Hamano.
 #
 
-USAGE='[--tool=tool] [--tool-help] [-y|--no-prompt|--prompt] [-O<orderfile>] [file to merge] ...'
+USAGE='[--tool=tool] [-g|--gui] [--tool-help] [-y|--no-prompt|--prompt] [-O<orderfile>] [file to merge] ...'
 SUBDIRECTORY_OK=Yes
 NONGIT_OK=Yes
 OPTIONS_SPEC=
@@ -414,6 +414,9 @@ main () {
 				shift ;;
 			esac
 			;;
+		-g|--gui)
+			merge_tool=$(git config merge.guitool)
+			;;
 		-y|--no-prompt)
 			prompt=false
 			;;
diff --git a/t/t7610-mergetool.sh b/t/t7610-mergetool.sh
index 381b7df45..5683907ab 100755
--- a/t/t7610-mergetool.sh
+++ b/t/t7610-mergetool.sh
@@ -123,7 +123,9 @@ test_expect_success 'setup' '
 	git config mergetool.mytool.cmd "cat \"\$REMOTE\" >\"\$MERGED\"" &&
 	git config mergetool.mytool.trustExitCode true &&
 	git config mergetool.mybase.cmd "cat \"\$BASE\" >\"\$MERGED\"" &&
-	git config mergetool.mybase.trustExitCode true
+	git config mergetool.mybase.trustExitCode true &&
+	git config mergetool.badtool.cmd false &&
+	git config mergetool.badtool.trustExitCode true
 '
 
 test_expect_success 'custom mergetool' '
@@ -145,6 +147,30 @@ test_expect_success 'custom mergetool' '
 	git commit -m "branch1 resolved with mergetool"
 '
 
+test_expect_success 'gui mergetool' '
+	test_when_finished "git reset --hard" &&
+	test_when_finished "git config merge.tool mytool" &&
+	test_when_finished "git config --unset merge.guitool" &&
+	git config merge.tool badtool &&
+	git config merge.guitool mytool &&
+	git checkout -b test$test_count branch1 &&
+	git submodule update -N &&
+	test_must_fail git merge master >/dev/null 2>&1 &&
+	( yes "" | git mergetool -g both >/dev/null 2>&1 ) &&
+	( yes "" | git mergetool -g file1 file1 ) &&
+	( yes "" | git mergetool --gui file2 "spaced name" >/dev/null 2>&1 ) &&
+	( yes "" | git mergetool --gui subdir/file3 >/dev/null 2>&1 ) &&
+	( yes "d" | git mergetool -g file11 >/dev/null 2>&1 ) &&
+	( yes "d" | git mergetool --gui file12 >/dev/null 2>&1 ) &&
+	( yes "l" | git mergetool --gui submod >/dev/null 2>&1 ) &&
+	cat file1 &&
+	test "$(cat file1)" = "master updated" &&
+	test "$(cat file2)" = "master new" &&
+	test "$(cat subdir/file3)" = "master new sub" &&
+	test "$(cat submod/bar)" = "branch1 submodule" &&
+	git commit -m "branch1 resolved with gui mergetool"
+'
+
 test_expect_success 'mergetool crlf' '
 	test_when_finished "git reset --hard" &&
 	# This test_config line must go after the above reset line so that
-- 
2.12.0.1.g5415fdfc5.dirty