1 files changed, 170 insertions, 0 deletions
diff --git a/t/t4020-diff-external.sh b/t/t4020-diff-external.sh
new file mode 100755
index 0000000000..083f62d1d6
--- /dev/null
+++ b/t/t4020-diff-external.sh
@@ -0,0 +1,170 @@
+#!/bin/sh
+
+test_description='external diff interface test'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+
+	test_tick &&
+	echo initial >file &&
+	git add file &&
+	git commit -m initial &&
+
+	test_tick &&
+	echo second >file &&
+	git add file &&
+	git commit -m second &&
+
+	test_tick &&
+	echo third >file
+'
+
+test_expect_success 'GIT_EXTERNAL_DIFF environment' '
+
+	GIT_EXTERNAL_DIFF=echo git diff | {
+		read path oldfile oldhex oldmode newfile newhex newmode &&
+		test "z$path" = zfile &&
+		test "z$oldmode" = z100644 &&
+		test "z$newhex" = "z$_z40" &&
+		test "z$newmode" = z100644 &&
+		oh=$(git rev-parse --verify HEAD:file) &&
+		test "z$oh" = "z$oldhex"
+	}
+
+'
+
+test_expect_success 'GIT_EXTERNAL_DIFF environment should apply only to diff' '
+
+	GIT_EXTERNAL_DIFF=echo git log -p -1 HEAD |
+	grep "^diff --git a/file b/file"
+
+'
+
+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 &&
+
+	echo >.gitattributes "file diff=parrot" &&
+
+	git diff | {
+		read path oldfile oldhex oldmode newfile newhex newmode &&
+		test "z$path" = zfile &&
+		test "z$oldmode" = z100644 &&
+		test "z$newhex" = "z$_z40" &&
+		test "z$newmode" = z100644 &&
+		oh=$(git rev-parse --verify HEAD:file) &&
+		test "z$oh" = "z$oldhex"
+	}
+
+'
+
+test_expect_success 'diff attribute should apply only to diff' '
+
+	git log -p -1 HEAD |
+	grep "^diff --git a/file b/file"
+
+'
+
+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 &&
+	git config diff.color.command echo &&
+
+	echo >.gitattributes "file diff=color" &&
+
+	git diff | {
+		read path oldfile oldhex oldmode newfile newhex newmode &&
+		test "z$path" = zfile &&
+		test "z$oldmode" = z100644 &&
+		test "z$newhex" = "z$_z40" &&
+		test "z$newmode" = z100644 &&
+		oh=$(git rev-parse --verify HEAD:file) &&
+		test "z$oh" = "z$oldhex"
+	}
+
+'
+
+test_expect_success 'diff attribute should apply only to diff' '
+
+	git log -p -1 HEAD |
+	grep "^diff --git a/file b/file"
+
+'
+
+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
+'
+
+echo NULZbetweenZwords | perl -pe 'y/Z/\000/' > file
+
+test_expect_success 'force diff with "diff"' '
+	echo >.gitattributes "file diff" &&
+	git diff >actual &&
+	test_cmp "$TEST_DIRECTORY"/t4020/diff.NUL actual
+'
+
+test_expect_success 'GIT_EXTERNAL_DIFF with more than one changed files' '
+	echo anotherfile > file2 &&
+	git add file2 &&
+	git commit -m "added 2nd file" &&
+	echo modified >file2 &&
+	GIT_EXTERNAL_DIFF=echo git diff
+'
+
+test_expect_success 'GIT_EXTERNAL_DIFF generates pretty paths' '
+	touch file.ext &&
+	git add file.ext &&
+	echo with extension > file.ext &&
+	GIT_EXTERNAL_DIFF=echo git diff file.ext | grep ......_file\.ext &&
+	git update-index --force-remove file.ext &&
+	rm file.ext
+'
+
+echo "#!$SHELL_PATH" >fake-diff.sh
+cat >> fake-diff.sh <<\EOF
+cat $2 >> crlfed.txt
+EOF
+chmod a+x fake-diff.sh
+
+keep_only_cr () {
+	tr -dc '\015'
+}
+
+test_expect_success 'external diff with autocrlf = true' '
+	git config core.autocrlf true &&
+	GIT_EXTERNAL_DIFF=./fake-diff.sh git diff &&
+	test $(wc -l < crlfed.txt) = $(cat crlfed.txt | keep_only_cr | wc -c)
+'
+
+test_expect_success 'diff --cached' '
+	git add file &&
+	git update-index --assume-unchanged file &&
+	echo second >file &&
+	git diff --cached >actual &&
+	test_cmp "$TEST_DIRECTORY"/t4020/diff.NUL actual
+'
+
+test_done