'
+test_expect_success 'GIT_EXTERNAL_DIFF environment and --no-ext-diff' '
+
+ GIT_EXTERNAL_DIFF=echo git diff --no-ext-diff |
+ grep "^diff --git a/file b/file"
+
+'
+
test_expect_success 'diff attribute' '
git config diff.parrot.command echo &&
'
+test_expect_success 'diff attribute and --no-ext-diff' '
+
+ git diff --no-ext-diff |
+ grep "^diff --git a/file b/file"
+
+'
+
test_expect_success 'diff attribute' '
git config --unset diff.parrot.command &&
'
+test_expect_success 'diff attribute and --no-ext-diff' '
+
+ git diff --no-ext-diff |
+ grep "^diff --git a/file b/file"
+
+'
+
test_expect_success 'no diff with -diff' '
echo >.gitattributes "file -diff" &&
git diff | grep Binary