In git-difftool.txt, it says
'git difftool' falls back to 'git mergetool' config variables when the
difftool equivalents have not been defined.
However, when `diff.guitool` is missing, it doesn't fallback to
anything. Make git-difftool fallback to `merge.guitool` when `diff.guitool` is
missing.
Signed-off-by: Denton Liu <liu.denton@xxxxxxxxx>
---
Documentation/git-difftool.txt | 4 +++-
builtin/difftool.c | 10 ++--------
t/t7800-difftool.sh | 16 ++++++++++++++++
3 files changed, 21 insertions(+), 9 deletions(-)
diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index 96c26e6aa8..484c485fd0 100644
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -90,7 +90,9 @@ instead. `--no-symlinks` is the default on Windows.
When 'git-difftool' is invoked with the `-g` or `--gui` option
the default diff tool will be read from the configured
`diff.guitool` variable instead of `diff.tool`. The `--no-gui`
- option can be used to override this setting.
+ option can be used to override this setting. If `diff.guitool`
+ is not set, we will fallback in the order of `merge.guitool`,
+ `diff.tool`, `merge.tool` until a tool is found.
--[no-]trust-exit-code::
'git-difftool' invokes a diff tool individually on each file.
diff --git a/builtin/difftool.c b/builtin/difftool.c
index 5ad39c9172..67f26502c5 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -24,7 +24,6 @@
#include "object-store.h"
#include "dir.h"
-static char *diff_gui_tool;
static int trust_exit_code;
static const char *const builtin_difftool_usage[] = {
@@ -34,11 +33,6 @@ static const char *const builtin_difftool_usage[] = {
static int difftool_config(const char *var, const char *value, void *cb)
{
- if (!strcmp(var, "diff.guitool")) {
- diff_gui_tool = xstrdup(value);
- return 0;
- }
-
if (!strcmp(var, "difftool.trustexitcode")) {
trust_exit_code = git_config_bool(var, value);
return 0;
@@ -740,8 +734,8 @@ int cmd_difftool(int argc, const char **argv, const char *prefix)
if (count > 1)
die(_("--gui, --tool and --extcmd are exclusive"));
- if (use_gui_tool && diff_gui_tool && *diff_gui_tool)
- setenv("GIT_DIFF_TOOL", diff_gui_tool, 1);
+ if (use_gui_tool)
+ setenv("GIT_MERGETOOL_GUI", "true", 1);
else if (difftool_cmd) {
if (*difftool_cmd)
setenv("GIT_DIFF_TOOL", difftool_cmd, 1);
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 107f31213d..ae90701a12 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -279,11 +279,27 @@ test_expect_success 'difftool + mergetool config variables' '
echo branch >expect &&
git difftool --no-prompt branch >actual &&
test_cmp expect actual &&
+ git difftool --gui --no-prompt branch >actual &&
+ test_cmp expect actual &&
# set merge.tool to something bogus, diff.tool to test-tool
test_config merge.tool bogus-tool &&
test_config diff.tool test-tool &&
git difftool --no-prompt branch >actual &&
+ test_cmp expect actual &&
+ git difftool --gui --no-prompt branch >actual &&
+ test_cmp expect actual &&
+
+ # set merge.tool, diff.tool to something bogus, merge.guitool to test-tool
+ test_config diff.tool bogus-tool &&
+ test_config merge.guitool test-tool &&
+ git difftool --gui --no-prompt branch >actual &&
+ test_cmp expect actual &&
+
+ # set merge.tool, diff.tool, merge.guitool to something bogus, diff.guitool to test-tool
+ test_config merge.guitool bogus-tool &&
+ test_config diff.guitool test-tool &&
+ git difftool --gui --no-prompt branch >actual &&
test_cmp expect actual
'
--
2.21.0.967.gf85e14fd49
