From a427ef7acc9d932d1c203dd2fae67f51c4b1d1e8 Mon Sep 17 00:00:00 2001
From: David Aguilar <davvid@gmail.com>
Date: Tue, 25 Sep 2012 00:48:11 -0700
Subject: mergetool--lib: Allow custom commands to override built-ins

Allow users to override the default commands provided by the
mergetools/* scriptlets.

Users occasionally run into problems where they expect to be
able to override the built-in tool names.  The documentation
does not explicitly mention that built-ins cannot be overridden,
so it's easy to assume that it should work.

Lift this restriction so that built-in tools are handled the
same way as user-configured tools.  Add tests to guarantee this
behavior.

A nice benefit of this change is that it protects users from
having future versions of git trump their custom configuration
with a new built-in tool.

C.f.:

http://stackoverflow.com/questions/7435002/mergetool-from-gitconfig-being-ignored
http://thread.gmane.org/gmane.comp.version-control.msysgit/13188
http://thread.gmane.org/gmane.comp.version-control.git/148267

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/t7610-mergetool.sh | 13 +++++++++++++
 t/t7800-difftool.sh  | 11 +++++++++++
 2 files changed, 24 insertions(+)

(limited to 't')

diff --git a/t/t7610-mergetool.sh b/t/t7610-mergetool.sh
index f5e16fc7db..0348ed2fb7 100755
--- a/t/t7610-mergetool.sh
+++ b/t/t7610-mergetool.sh
@@ -471,4 +471,17 @@ test_expect_success 'file with no base' '
     git reset --hard master >/dev/null 2>&1
 '
 
+test_expect_success 'custom commands override built-ins' '
+    git checkout -b test14 branch1 &&
+    git config mergetool.defaults.cmd "cat \"\$REMOTE\" >\"\$MERGED\"" &&
+    git config mergetool.defaults.trustExitCode true &&
+    test_must_fail git merge master &&
+    git mergetool --no-prompt --tool defaults -- both &&
+    echo master both added >expected &&
+    test_cmp both expected &&
+    git config --unset mergetool.defaults.cmd &&
+    git config --unset mergetool.defaults.trustExitCode &&
+    git reset --hard master >/dev/null 2>&1
+'
+
 test_done
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 9c3e997b9d..eb1d3f85b5 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -76,6 +76,17 @@ test_expect_success PERL 'custom commands' '
 	test "$diff" = "branch"
 '
 
+# Ensures that a custom difftool.<tool>.cmd overrides built-ins
+test_expect_success PERL 'custom commands override built-ins' '
+	restore_test_defaults &&
+	git config difftool.defaults.cmd "cat \$REMOTE" &&
+
+	diff=$(git difftool --tool defaults --no-prompt branch) &&
+	test "$diff" = "master" &&
+
+	git config --unset difftool.defaults.cmd
+'
+
 # Ensures that git-difftool ignores bogus --tool values
 test_expect_success PERL 'difftool ignores bad --tool values' '
 	diff=$(git difftool --no-prompt --tool=bad-tool branch)
-- 
cgit v1.2.3