Merge branch 'js/stash-p-fix'

Allowing the user to split a patch hunk while "git stash -p" does
not work well; a band-aid has been added to make this (partially)
work better.

* js/stash-p-fix:
  stash -p: (partially) fix bug concerning split hunks
  t3904: fix incorrect demonstration of a bug

Author: gitster

builtin/stash.c

@@ -1041,7 +1041,7 @@ static int stash_patch(struct stash_info *info, const struct pathspec *ps,
 	}
 
 	cp_diff_tree.git_cmd = 1;
-	argv_array_pushl(&cp_diff_tree.args, "diff-tree", "-p", "HEAD",
+	argv_array_pushl(&cp_diff_tree.args, "diff-tree", "-p", "-U1", "HEAD",
 			 oid_to_hex(&info->w_tree), "--", NULL);
 	if (pipe_command(&cp_diff_tree, NULL, 0, out_patch, 0, NULL, 0)) {
 		ret = -1;

t/t3904-stash-patch.sh

@@ -89,7 +89,7 @@ test_expect_success 'none of this moved HEAD' '
 	verify_saved_head
 '
 
-test_expect_failure 'stash -p with split hunk' '
+test_expect_success 'stash -p with split hunk' '
 	git reset --hard &&
 	cat >test <<-\EOF &&
 	aaa
@@ -106,8 +106,8 @@ test_expect_failure 'stash -p with split hunk' '
 	ccc
 	EOF
 	printf "%s\n" s n y q |
-	test_might_fail git stash -p 2>error &&
-	! test_must_be_empty error &&
+	git stash -p 2>error &&
+	test_must_be_empty error &&
 	grep "added line 1" test &&
 	! grep "added line 2" test
 '