From 8f0cb41da26c1e20cfbcfded030d6539464b132e Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Sat, 11 Oct 2014 10:04:45 -0700
Subject: mergetool: add an option for writing to a temporary directory

Teach mergetool to write files in a temporary directory when
'mergetool.writeToTemp' is true.

This is helpful for tools such as Eclipse which cannot cope with
multiple copies of the same file in the worktree.

Suggested-by: Charles Bailey <charles@hashpling.org>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/config.txt b/Documentation/config.txt
index c08286e..c305aff 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -1755,6 +1755,12 @@ mergetool.keepTemporaries::
 	preserved, otherwise they will be removed after the tool has
 	exited. Defaults to `false`.
 
+mergetool.writeToTemp::
+	Git writes temporary 'BASE', 'LOCAL', and 'REMOTE' versions of
+	conflicting files in the worktree by default.  Git will attempt
+	to use a temporary directory for these files when set `true`.
+	Defaults to `false`.
+
 mergetool.prompt::
 	Prompt before each invocation of the merge resolution program.
 
diff --git a/git-mergetool.sh b/git-mergetool.sh
index 0ff6566..83863f2 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -37,6 +37,19 @@ base_present () {
 	test -n "$base_mode"
 }
 
+mergetool_tmpdir_init () {
+	if test "$(git config --bool mergetool.writeToTemp)" != true
+	then
+		MERGETOOL_TMPDIR=.
+		return 0
+	fi
+	if MERGETOOL_TMPDIR=$(mktemp -d -t "git-mergetool-XXXXXX" 2>/dev/null)
+	then
+		return 0
+	fi
+	die "error: mktemp is needed when 'mergetool.writeToTemp' is true"
+}
+
 cleanup_temp_files () {
 	if test "$1" = --save-backup
 	then
@@ -46,6 +59,10 @@ cleanup_temp_files () {
 	else
 		rm -f -- "$LOCAL" "$REMOTE" "$BASE" "$BACKUP"
 	fi
+	if test "$MERGETOOL_TMPDIR" != "."
+	then
+		rmdir "$MERGETOOL_TMPDIR"
+	fi
 }
 
 describe_file () {
@@ -235,10 +252,20 @@ merge_file () {
 		BASE=$MERGED
 		ext=
 	fi
-	BACKUP="./${BASE}_BACKUP_$$$ext"
-	LOCAL="./${BASE}_LOCAL_$$$ext"
-	REMOTE="./${BASE}_REMOTE_$$$ext"
-	BASE="./${BASE}_BASE_$$$ext"
+
+	mergetool_tmpdir_init
+
+	if test "$MERGETOOL_TMPDIR" != "."
+	then
+		# If we're using a temporary directory then write to the
+		# top-level of that directory.
+		BASE=${BASE##*/}
+	fi
+
+	BACKUP="$MERGETOOL_TMPDIR/${BASE}_BACKUP_$$$ext"
+	LOCAL="$MERGETOOL_TMPDIR/${BASE}_LOCAL_$$$ext"
+	REMOTE="$MERGETOOL_TMPDIR/${BASE}_REMOTE_$$$ext"
+	BASE="$MERGETOOL_TMPDIR/${BASE}_BASE_$$$ext"
 
 	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;}')
-- 
cgit v0.10.2-6-g49f6


From 688684eba436c021eaddab1725093bb953cf260d Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Wed, 15 Oct 2014 01:35:19 -0700
Subject: t7610-mergetool: add test cases for mergetool.writeToTemp

Add tests to ensure that filenames start with "./" when
mergetool.writeToTemp is false and do not start with "./" when
mergetool.writeToTemp is true.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t7610-mergetool.sh b/t/t7610-mergetool.sh
index 2834ded..4fec633 100755
--- a/t/t7610-mergetool.sh
+++ b/t/t7610-mergetool.sh
@@ -514,4 +514,27 @@ test_expect_success 'custom commands override built-ins' '
 	git reset --hard master >/dev/null 2>&1
 '
 
+test_expect_success 'filenames seen by tools start with ./' '
+	git checkout -b test15 branch1 &&
+	test_config mergetool.writeToTemp false &&
+	test_config mergetool.myecho.cmd "echo \"\$LOCAL\"" &&
+	test_config mergetool.myecho.trustExitCode true &&
+	test_must_fail git merge master &&
+	git mergetool --no-prompt --tool myecho -- both >actual &&
+	grep ^\./both_LOCAL_ actual >/dev/null &&
+	git reset --hard master >/dev/null 2>&1
+'
+
+test_expect_success 'temporary filenames are used with mergetool.writeToTemp' '
+	git checkout -b test16 branch1 &&
+	test_config mergetool.writeToTemp true &&
+	test_config mergetool.myecho.cmd "echo \"\$LOCAL\"" &&
+	test_config mergetool.myecho.trustExitCode true &&
+	test_must_fail git merge master &&
+	git mergetool --no-prompt --tool myecho -- both >actual &&
+	test_must_fail grep ^\./both_LOCAL_ actual >/dev/null &&
+	grep /both_LOCAL_ actual >/dev/null &&
+	git reset --hard master >/dev/null 2>&1
+'
+
 test_done
-- 
cgit v0.10.2-6-g49f6