difftool: make --gui, --tool and --extcmd mutually exclusive
In git-difftool, these options specify which tool to ultimately run. As
a result, they are logically conflicting. Explicitly disallow these
options from being used together.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/difftool.c b/builtin/difftool.c
index 544b0e8..481aa64 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -730,6 +730,9 @@
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 + !!difftool_cmd + !!extcmd > 1)
+ die(_("--gui, --tool and --extcmd are mutually exclusive"));
+
if (use_gui_tool && diff_gui_tool && *diff_gui_tool)
setenv("GIT_DIFF_TOOL", diff_gui_tool, 1);
else if (difftool_cmd) {
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 562bd21..833e175 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -705,4 +705,12 @@
test_cmp expect actual
'
+test_expect_success 'difftool --gui, --tool and --extcmd are mutually exclusive' '
+ difftool_test_setup &&
+ test_must_fail git difftool --gui --tool=test-tool &&
+ test_must_fail git difftool --gui --extcmd=cat &&
+ test_must_fail git difftool --tool=test-tool --extcmd=cat &&
+ test_must_fail git difftool --gui --tool=test-tool --extcmd=cat
+'
+
test_done
