Merge branch 'tk/mergetool-gui-default-config'

[thirdparty/git.git] / builtin / difftool.c

diff --git a/builtin/difftool.c b/builtin/difftool.c
index e010a21bfbc1c4dacc70c9e1866ad4f109af737b..5ba524fa639cdd30dd6f6fa846519370fecc2510 100644 (file)
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -691,7 +691,7 @@ 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,
+       int use_gui_tool = -1, dir_diff = 0, prompt = -1, symlinks = 0,
            tool_help = 0, no_index = 0;
        static char *difftool_cmd = NULL, *extcmd = NULL;
        struct option builtin_difftool_options[] = {
@@ -741,13 +741,21 @@ int cmd_difftool(int argc, const char **argv, const char *prefix)
        } else if (dir_diff)
                die(_("options '%s' and '%s' cannot be used together"), "--dir-diff", "--no-index");
 
-       die_for_incompatible_opt3(use_gui_tool, "--gui",
+       die_for_incompatible_opt3(use_gui_tool == 1, "--gui",
                                  !!difftool_cmd, "--tool",
                                  !!extcmd, "--extcmd");
 
-       if (use_gui_tool)
+       /*
+        * Explicitly specified GUI option is forwarded to git-mergetool--lib.sh;
+        * empty or unset means "use the difftool.guiDefault config or default to
+        * false".
+        */
+       if (use_gui_tool == 1)
                setenv("GIT_MERGETOOL_GUI", "true", 1);
-       else if (difftool_cmd) {
+       else if (use_gui_tool == 0)
+               setenv("GIT_MERGETOOL_GUI", "false", 1);
+
+       if (difftool_cmd) {
                if (*difftool_cmd)
                        setenv("GIT_DIFF_TOOL", difftool_cmd, 1);
                else