Merge branch 'en/merge-path-collision'

Updates for corner cases in merge-recursive.

* en/merge-path-collision:
  t6036: avoid non-portable "cp -a"
  merge-recursive: combine error handling
  t6036, t6043: increase code coverage for file collision handling
  merge-recursive: improve rename/rename(1to2)/add[/add] handling
  merge-recursive: use handle_file_collision for add/add conflicts
  merge-recursive: improve handling for rename/rename(2to1) conflicts
  merge-recursive: fix rename/add conflict handling
  merge-recursive: new function for better colliding conflict resolutions
  merge-recursive: increase marker length with depth of recursion
  t6036, t6042: testcases for rename collision of already conflicting files
  t6042: add tests for consistency in file collision conflict handling

1 files changed, 100 insertions, 44 deletions

diff --git a/t/t6043-merge-rename-directories.sh b/t/t6043-merge-rename-directories.sh
index 4a71f17edd..62c564707b 100755
--- a/t/t6043-merge-rename-directories.sh
+++ b/t/t6043-merge-rename-directories.sh
@@ -278,7 +278,7 @@ test_expect_success '1d-check: Directory renames cause a rename/rename(2to1) con
 		git ls-files -u >out &&
 		test_line_count = 2 out &&
 		git ls-files -o >out &&
-		test_line_count = 3 out &&
+		test_line_count = 1 out &&
 
 		git rev-parse >actual \
 			:0:x/b :0:x/c :0:x/d :0:x/e :0:x/m :0:x/n &&
@@ -293,15 +293,16 @@ test_expect_success '1d-check: Directory renames cause a rename/rename(2to1) con
 			 A:y/wham  B:z/wham &&
 		test_cmp expect actual &&
 
-		test_path_is_missing x/wham &&
-		test_path_is_file x/wham~HEAD &&
-		test_path_is_file x/wham~B^0 &&
-
-		git hash-object >actual \
-			x/wham~HEAD x/wham~B^0 &&
-		git rev-parse >expect \
-			A:y/wham    B:z/wham &&
-		test_cmp expect actual
+		# Test that the two-way merge in x/wham is as expected
+		git cat-file -p :2:x/wham >expect &&
+		git cat-file -p :3:x/wham >other &&
+		>empty &&
+		test_must_fail git merge-file \
+			-L "HEAD" \
+			-L "" \
+			-L "B^0" \
+			expect empty other &&
+		test_cmp expect x/wham
 	)
 '
 
@@ -1077,7 +1078,7 @@ test_expect_success '5c-check: Transitive rename would cause rename/rename/renam
 		git ls-files -u >out &&
 		test_line_count = 6 out &&
 		git ls-files -o >out &&
-		test_line_count = 3 out &&
+		test_line_count = 1 out &&
 
 		git rev-parse >actual \
 			:0:y/b :0:y/c :0:y/e &&
@@ -1093,9 +1094,9 @@ test_expect_success '5c-check: Transitive rename would cause rename/rename/renam
 		test_cmp expect actual &&
 
 		git hash-object >actual \
-			w/d~HEAD w/d~B^0 z/d &&
+			z/d &&
 		git rev-parse >expect \
-			O:x/d    B:w/d   O:x/d &&
+			O:x/d &&
 		test_cmp expect actual &&
 		test_path_is_missing x/d &&
 		test_path_is_file y/d &&
@@ -1670,7 +1671,7 @@ test_expect_success '7b-check: rename/rename(2to1), but only due to transitive r
 		git ls-files -u >out &&
 		test_line_count = 2 out &&
 		git ls-files -o >out &&
-		test_line_count = 3 out &&
+		test_line_count = 1 out &&
 
 		git rev-parse >actual \
 			:0:y/b :0:y/c :2:y/d :3:y/d &&
@@ -1678,15 +1679,16 @@ test_expect_success '7b-check: rename/rename(2to1), but only due to transitive r
 			 O:z/b  O:z/c  O:w/d  O:x/d &&
 		test_cmp expect actual &&
 
-		test_path_is_missing y/d &&
-		test_path_is_file y/d~HEAD &&
-		test_path_is_file y/d~B^0 &&
-
-		git hash-object >actual \
-			y/d~HEAD y/d~B^0 &&
-		git rev-parse >expect \
-			O:w/d    O:x/d &&
-		test_cmp expect actual
+		# Test that the two-way merge in y/d is as expected
+		git cat-file -p :2:y/d >expect &&
+		git cat-file -p :3:y/d >other &&
+		>empty &&
+		test_must_fail git merge-file \
+			-L "HEAD" \
+			-L "" \
+			-L "B^0" \
+			expect empty other &&
+		test_cmp expect y/d
 	)
 '
 
@@ -3161,11 +3163,48 @@ test_expect_success '10c-check: Overwrite untracked with dir rename/rename(1to2)
 	)
 '
 
+test_expect_success '10c-check: Overwrite untracked with dir rename/rename(1to2), other direction' '
+	(
+		cd 10c &&
+
+		git reset --hard &&
+		git clean -fdqx &&
+
+		git checkout B^0 &&
+		mkdir y &&
+		echo important >y/c &&
+
+		test_must_fail git merge -s recursive A^0 >out 2>err &&
+		test_i18ngrep "CONFLICT (rename/rename)" out &&
+		test_i18ngrep "Refusing to lose untracked file at y/c; adding as y/c~HEAD instead" out &&
+
+		git ls-files -s >out &&
+		test_line_count = 6 out &&
+		git ls-files -u >out &&
+		test_line_count = 3 out &&
+		git ls-files -o >out &&
+		test_line_count = 3 out &&
+
+		git rev-parse >actual \
+			:0:y/a :0:y/b :0:x/d :1:x/c :3:w/c :2:y/c &&
+		git rev-parse >expect \
+			 O:z/a  O:z/b  O:x/d  O:x/c  O:x/c  O:x/c &&
+		test_cmp expect actual &&
+
+		git hash-object y/c~HEAD >actual &&
+		git rev-parse O:x/c >expect &&
+		test_cmp expect actual &&
+
+		echo important >expect &&
+		test_cmp expect y/c
+	)
+'
+
 # Testcase 10d, Delete untracked w/ dir rename/rename(2to1)
 #   Commit O: z/{a,b,c_1},        x/{d,e,f_2}
 #   Commit A: y/{a,b},            x/{d,e,f_2,wham_1} + untracked y/wham
 #   Commit B: z/{a,b,c_1,wham_2}, y/{d,e}
-#   Expected: Failed Merge; y/{a,b,d,e} + untracked y/{wham,wham~B^0,wham~HEAD}+
+#   Expected: Failed Merge; y/{a,b,d,e} + untracked y/{wham,wham~merged}+
 #             CONFLICT(rename/rename) z/c_1 vs x/f_2 -> y/wham
 #             ERROR_MSG(Refusing to lose untracked file at y/wham)
 
@@ -3219,7 +3258,7 @@ test_expect_success '10d-check: Delete untracked with dir rename/rename(2to1)' '
 		git ls-files -u >out &&
 		test_line_count = 2 out &&
 		git ls-files -o >out &&
-		test_line_count = 4 out &&
+		test_line_count = 3 out &&
 
 		git rev-parse >actual \
 			:0:y/a :0:y/b :0:y/d :0:y/e :2:y/wham :3:y/wham &&
@@ -3232,11 +3271,16 @@ test_expect_success '10d-check: Delete untracked with dir rename/rename(2to1)' '
 		echo important >expect &&
 		test_cmp expect y/wham &&
 
-		git hash-object >actual \
-			y/wham~B^0 y/wham~HEAD &&
-		git rev-parse >expect \
-			O:x/f      O:z/c &&
-		test_cmp expect actual
+		# Test that the two-way merge in y/wham~merged is as expected
+		git cat-file -p :2:y/wham >expect &&
+		git cat-file -p :3:y/wham >other &&
+		>empty &&
+		test_must_fail git merge-file \
+			-L "HEAD" \
+			-L "" \
+			-L "B^0" \
+			expect empty other &&
+		test_cmp expect y/wham~merged
 	)
 '
 
@@ -3665,7 +3709,7 @@ test_expect_success '11e-check: Avoid deleting not-uptodate with dir rename/rena
 		git ls-files -u >out &&
 		test_line_count = 4 out &&
 		git ls-files -o >out &&
-		test_line_count = 4 out &&
+		test_line_count = 3 out &&
 
 		echo different >expected &&
 		echo mods >>expected &&
@@ -3677,11 +3721,17 @@ test_expect_success '11e-check: Avoid deleting not-uptodate with dir rename/rena
 			 O:z/a  O:z/b  O:x/d  O:x/c  O:x/c  A:y/c  O:x/c &&
 		test_cmp expect actual &&
 
-		git hash-object >actual \
-			y/c~B^0 y/c~HEAD &&
-		git rev-parse >expect \
-			O:x/c   A:y/c &&
-		test_cmp expect actual
+		# See if y/c~merged has expected contents; requires manually
+		# doing the expected file merge
+		git cat-file -p A:y/c >c1 &&
+		git cat-file -p B:z/c >c2 &&
+		>empty &&
+		test_must_fail git merge-file \
+			-L "HEAD" \
+			-L "" \
+			-L "B^0" \
+			c1 empty c2 &&
+		test_cmp c1 y/c~merged
 	)
 '
 
@@ -3689,7 +3739,7 @@ test_expect_success '11e-check: Avoid deleting not-uptodate with dir rename/rena
 #   Commit O: z/{a,b},        x/{c_1,d_2}
 #   Commit A: y/{a,b,wham_1}, x/d_2, except y/wham has uncommitted mods
 #   Commit B: z/{a,b,wham_2}, x/c_1
-#   Expected: Failed Merge; y/{a,b} + untracked y/{wham~B^0,wham~B^HEAD} +
+#   Expected: Failed Merge; y/{a,b} + untracked y/{wham~merged} +
 #             y/wham with dirty changes from before merge +
 #             CONFLICT(rename/rename) x/c vs x/d -> y/wham
 #             ERROR_MSG(Refusing to lose dirty file at y/wham)
@@ -3741,24 +3791,30 @@ test_expect_success '11f-check: Avoid deleting not-uptodate with dir rename/rena
 		git ls-files -u >out &&
 		test_line_count = 2 out &&
 		git ls-files -o >out &&
-		test_line_count = 4 out &&
+		test_line_count = 3 out &&
 
 		test_seq 1 10 >expected &&
 		echo important >>expected &&
 		test_cmp expected y/wham &&
 
 		test_must_fail git rev-parse :1:y/wham &&
-		git hash-object >actual \
-			y/wham~B^0 y/wham~HEAD &&
-		git rev-parse >expect \
-			O:x/d      O:x/c &&
-		test_cmp expect actual &&
 
 		git rev-parse >actual \
 			:0:y/a :0:y/b :2:y/wham :3:y/wham &&
 		git rev-parse >expect \
 			 O:z/a  O:z/b  O:x/c     O:x/d &&
-		test_cmp expect actual
+		test_cmp expect actual &&
+
+		# Test that the two-way merge in y/wham~merged is as expected
+		git cat-file -p :2:y/wham >expect &&
+		git cat-file -p :3:y/wham >other &&
+		>empty &&
+		test_must_fail git merge-file \
+			-L "HEAD" \
+			-L "" \
+			-L "B^0" \
+			expect empty other &&
+		test_cmp expect y/wham~merged
 	)
 '