Merge branch 'da/mergetool-custom'

The actual external command to run for mergetool backend can be
specified with difftool/mergetool.$name.cmd configuration
variables, but this mechanism was ignored for the backends we
natively support.

* da/mergetool-custom:
  mergetool--lib: Allow custom commands to override built-ins

2 files changed, 24 insertions, 0 deletions

diff --git a/t/t7610-mergetool.sh b/t/t7610-mergetool.sh
index 6fa0c70506..bc38737b2a 100755
--- a/t/t7610-mergetool.sh
+++ b/t/t7610-mergetool.sh
@@ -509,4 +509,17 @@ 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)