add -p: coalesce hunks before testing applicability

When a hunk was split before being edited manually, it does not apply
anymore cleanly. Apply coalesce_overlapping_hunks() first to make it
work. Enable test for it as well.

Signed-off-by: Jochen Sprickerhof <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: jspricke

git-add--interactive.perl

@@ -1188,10 +1188,10 @@ sub edit_hunk_loop {
 		# delta from the original unedited hunk.
 		$hunk->{OFS_DELTA} and
 				$newhunk->{OFS_DELTA} += $hunk->{OFS_DELTA};
-		if (diff_applies($head,
-				 @{$hunks}[0..$ix-1],
-				 $newhunk,
-				 @{$hunks}[$ix+1..$#{$hunks}])) {
+		my @hunk = @{$hunks};
+		splice (@hunk, $ix, 1, $newhunk);
+		@hunk = coalesce_overlapping_hunks(@hunk);
+		if (diff_applies($head, @hunk)) {
 			$newhunk->{DISPLAY} = [color_diff(@{$newtext})];
 			return $newhunk;
 		}

t/t3701-add-interactive.sh

@@ -348,7 +348,7 @@ test_expect_success 'split hunk "add -p (edit)"' '
 	! grep "^+15" actual
 '
 
-test_expect_failure 'split hunk "add -p (no, yes, edit)"' '
+test_expect_success 'split hunk "add -p (no, yes, edit)"' '
 	test_write_lines 5 10 20 21 30 31 40 50 60 >test &&
 	git reset &&
 	# test sequence is s(plit), n(o), y(es), e(dit)