[PATCH 2/2] difftool: allow running outside Git worktrees with --no-index

From

Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>

Date

Mar 13, 2019, 19:20 UTC

Message-ID

<9f6eb60eeeccf920af83652899c5bc2d40e2092f.1552504812.git.gitgitgadget@gmail.com>

In-Reply-To

<pull.163.git.gitgitgadget@gmail.com>

From: Johannes Schindelin <johannes.schindelin@gmx.de>

This fixes https://github.com/git-for-windows/git/issues/2123

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 builtin/difftool.c  | 20 +++++++++++++++++---
 git.c               |  2 +-
 t/t7800-difftool.sh | 10 ++++++++++
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/builtin/difftool.c b/builtin/difftool.c
index 31eece0c8d..d08ef31f04 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -690,7 +690,7 @@ static int run_file_diff(int prompt, const char *prefix,
 int cmd_difftool(int argc, const char **argv, const char *prefix)
 {
 	int use_gui_tool = 0, dir_diff = 0, prompt = -1, symlinks = 0,
-	    tool_help = 0;
+	    tool_help = 0, i, no_index = 0;
 	static char *difftool_cmd = NULL, *extcmd = NULL;
 	struct option builtin_difftool_options[] = {
 		OPT_BOOL('g', "gui", &use_gui_tool,
@@ -727,8 +727,22 @@ int cmd_difftool(int argc, const char **argv, const char *prefix)
 	if (tool_help)
 		return print_tool_help();
 
-	setenv(GIT_DIR_ENVIRONMENT, absolute_path(get_git_dir()), 1);
-	setenv(GIT_WORK_TREE_ENVIRONMENT, absolute_path(get_git_work_tree()), 1);
+	for (i = 0; i < argc; i++)
+		if (!strcmp(argv[i], "--"))
+			break;
+		else if (!strcmp(argv[i], "--no-index")) {
+			no_index = 1;
+			break;
+		}
+
+	if (!no_index && !startup_info->have_repository)
+		die(_("difftool requires worktree or --no-index"));
+
+	if (!no_index){
+		setup_work_tree();
+		setenv(GIT_DIR_ENVIRONMENT, absolute_path(get_git_dir()), 1);
+		setenv(GIT_WORK_TREE_ENVIRONMENT, absolute_path(get_git_work_tree()), 1);
+	}
 
 	if (use_gui_tool && diff_gui_tool && *diff_gui_tool)
 		setenv("GIT_DIFF_TOOL", diff_gui_tool, 1);
diff --git a/git.c b/git.c
index 2014aab6b8..46365ed86a 100644
--- a/git.c
+++ b/git.c
@@ -491,7 +491,7 @@ static struct cmd_struct commands[] = {
 	{ "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
 	{ "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
 	{ "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
-	{ "difftool", cmd_difftool, RUN_SETUP | NEED_WORK_TREE },
+	{ "difftool", cmd_difftool, RUN_SETUP_GENTLY },
 	{ "fast-export", cmd_fast_export, RUN_SETUP },
 	{ "fetch", cmd_fetch, RUN_SETUP },
 	{ "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index bb9a7f4ff9..4907627656 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -705,4 +705,14 @@ test_expect_success SYMLINKS 'difftool --dir-diff handles modified symlinks' '
 	test_cmp expect actual
 '
 
+test_expect_success 'outside worktree' '
+	mkdir outside &&
+	echo 1 >outside/1 &&
+	echo 2 >outside/2 &&
+	test_expect_code 1 env GIT_CEILING_DIRECTORIES="$(pwd)" git \
+		-c diff.tool=echo -c difftool.echo.cmd="echo \$LOCAL \$REMOTE" \
+		-C outside difftool --no-prompt --no-index 1 2 >out &&
+	test "1 2" = "$(cat out)"
+'
+
 test_done

-- 
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