1 files changed, 270 insertions, 0 deletions
diff --git a/t/t4020-diff-external.sh b/t/t4020-diff-external.sh
new file mode 100755
index 0000000000..044620186d
--- /dev/null
+++ b/t/t4020-diff-external.sh
@@ -0,0 +1,270 @@
+#!/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 SYMLINKS 'typechange diff' '
+	rm -f file &&
+	ln -s elif file &&
+	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$newmode" = z120000 &&
+		oh=$(git rev-parse --verify HEAD:file) &&
+		test "z$oh" = "z$oldhex"
+	} &&
+	GIT_EXTERNAL_DIFF=echo git diff --no-ext-diff >actual &&
+	git diff >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'diff.external' '
+	git reset --hard &&
+	echo third >file &&
+	test_config diff.external 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 'diff.external should apply only to diff' '
+	test_config diff.external echo &&
+	git log -p -1 HEAD |
+	grep "^diff --git a/file b/file"
+'
+
+test_expect_success 'diff.external and --no-ext-diff' '
+	test_config diff.external echo &&
+	git diff --no-ext-diff |
+	grep "^diff --git a/file b/file"
+'
+
+test_expect_success 'diff attribute' '
+	git reset --hard &&
+	echo third >file &&
+
+	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 'GIT_EXTERNAL_DIFF trumps diff.external' '
+	>.gitattributes &&
+	test_config diff.external "echo ext-global" &&
+	GIT_EXTERNAL_DIFF="echo ext-env" git diff | grep ext-env
+'
+
+test_expect_success 'attributes trump GIT_EXTERNAL_DIFF and diff.external' '
+	test_config diff.foo.command "echo ext-attribute" &&
+	test_config diff.external "echo ext-global" &&
+	echo "file diff=foo" >.gitattributes &&
+	GIT_EXTERNAL_DIFF="echo ext-env" git diff | grep ext-attribute
+'
+
+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 path counter/total' '
+	write_script external-diff.sh <<-\EOF &&
+	echo $GIT_DIFF_PATH_COUNTER of $GIT_DIFF_PATH_TOTAL >>counter.txt
+	EOF
+	>counter.txt &&
+	cat >expect <<-\EOF &&
+	1 of 2
+	2 of 2
+	EOF
+	GIT_EXTERNAL_DIFF=./external-diff.sh git diff &&
+	test_cmp expect counter.txt
+'
+
+test_expect_success 'GIT_EXTERNAL_DIFF generates pretty paths' '
+	touch file.ext &&
+	git add file.ext &&
+	echo with extension > file.ext &&
+	GIT_EXTERNAL_DIFF=echo git diff file.ext | grep ......_file\.ext &&
+	git update-index --force-remove file.ext &&
+	rm file.ext
+'
+
+echo "#!$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' '
+	test_config core.autocrlf true &&
+	GIT_EXTERNAL_DIFF=./fake-diff.sh git diff &&
+	test $(wc -l < crlfed.txt) = $(cat crlfed.txt | keep_only_cr | wc -c)
+'
+
+test_expect_success 'diff --cached' '
+	test_config core.autocrlf true &&
+	git add file &&
+	git update-index --assume-unchanged file &&
+	echo second >file &&
+	git diff --cached >actual &&
+	test_cmp "$TEST_DIRECTORY"/t4020/diff.NUL actual
+'
+
+test_expect_success 'clean up crlf leftovers' '
+	git update-index --no-assume-unchanged file &&
+	rm -f file* &&
+	git reset --hard
+'
+
+test_expect_success 'submodule diff' '
+	git init sub &&
+	( cd sub && test_commit sub1 ) &&
+	git add sub &&
+	test_tick &&
+	git commit -m "add submodule" &&
+	( cd sub && test_commit sub2 ) &&
+	write_script gather_pre_post.sh <<-\EOF &&
+	echo "$1 $4" # path, mode
+	cat "$2" # old file
+	cat "$5" # new file
+	EOF
+	GIT_EXTERNAL_DIFF=./gather_pre_post.sh git diff >actual &&
+	cat >expected <<-EOF &&
+	sub 160000
+	Subproject commit $(git rev-parse HEAD:sub)
+	Subproject commit $(cd sub && git rev-parse HEAD)
+	EOF
+	test_cmp expected actual
+'
+
+test_done