t4140: test apply --intent-to-add interactions

Test that applying a new file creation patch with --intent-to-add to
an existing index does not modify the index outside adding the correct
intents-to-add, and that applying a patch with both modifications
and new file creations with --intent-to-add correctly only adds
intents-to-add to the index.

Signed-off-by: Raymond E. Pasco <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: juped

t/t4140-apply-ita.sh

@@ -7,14 +7,25 @@ test_description='git apply of i-t-a file'
 test_expect_success setup '
 	test_write_lines 1 2 3 4 5 >blueprint &&
 
+	cat blueprint >committed-file &&
+	git add committed-file &&
+	git commit -m "commit" &&
+
 	cat blueprint >test-file &&
 	git add -N test-file &&
 	git diff >creation-patch &&
 	grep "new file mode 100644" creation-patch &&
 
 	rm -f test-file &&
 	git diff >deletion-patch &&
-	grep "deleted file mode 100644" deletion-patch
+	grep "deleted file mode 100644" deletion-patch &&
+
+	git rm -f test-file &&
+	test_write_lines 6 >>committed-file &&
+	cat blueprint >test-file &&
+	git add -N test-file &&
+	git diff >complex-patch &&
+	git restore committed-file
 '
 
 test_expect_success 'apply creation patch to ita path (--cached)' '
@@ -53,4 +64,22 @@ test_expect_success 'apply deletion patch to ita path (--index)' '
 	git ls-files --stage --error-unmatch test-file
 '
 
+test_expect_success 'apply creation patch to existing index with -N' '
+	git rm -f test-file &&
+	cat blueprint >index-file &&
+	git add index-file &&
+	git apply -N creation-patch &&
+
+	git ls-files --stage --error-unmatch index-file &&
+	git ls-files --stage --error-unmatch test-file
+'
+
+test_expect_success 'apply complex patch with -N' '
+	git rm -f test-file index-file &&
+	git apply -N complex-patch &&
+
+	git ls-files --stage --error-unmatch test-file &&
+	git diff | grep "a/committed-file"
+'
+
 test_done