merge_recursive: Fix renames across paths below D/F conflicts

The rename logic in process_renames() handles renames and merging of file
contents and then marks files as processed.  However, there may be higher
stage entries left in the index for other reasons (e.g., due to D/F
conflicts).  By checking for such cases and marking the entry as not
processed, it allows process_entry() later to look at it and handle those
higher stages.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

merge-recursive.c

@@ -1019,14 +1019,25 @@ static int process_renames(struct merge_options *o,
 
 				if (mfi.clean &&
 				    sha_eq(mfi.sha, ren1->pair->two->sha1) &&
-				    mfi.mode == ren1->pair->two->mode)
+				    mfi.mode == ren1->pair->two->mode) {
 					/*
 					 * This messaged is part of
 					 * t6022 test. If you change
 					 * it update the test too.
 					 */
 					output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
-				else {
+
+					/* There may be higher stage entries left
+					 * in the index (e.g. due to a D/F
+					 * conflict) that need to be resolved.
+					 */
+					for (i = 1; i <= 3; i++) {
+						if (!ren1->dst_entry->stages[i].mode)
+							continue;
+						ren1->dst_entry->processed = 0;
+						break;
+					}
+				} else {
 					if (mfi.merge || !mfi.clean)
 						output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
 					if (mfi.merge)

t/t3509-cherry-pick-merge-df.sh

@@ -26,7 +26,7 @@ test_expect_success 'Setup rename across paths each below D/F conflicts' '
 	git commit -m f1
 '
 
-test_expect_failure 'Cherry-pick succeeds with rename across D/F conflicts' '
+test_expect_success 'Cherry-pick succeeds with rename across D/F conflicts' '
 	git reset --hard &&
 	git checkout master^0 &&
 	git cherry-pick branch

t/t6020-merge-df.sh

@@ -22,7 +22,7 @@ git commit -m "File: dir"'
 
 test_expect_code 1 'Merge with d/f conflicts' 'git merge "merge msg" B master'
 
-test_expect_failure 'F/D conflict' '
+test_expect_success 'F/D conflict' '
 	git reset --hard &&
 	git checkout master &&
 	rm .git/index &&