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[PATCH 37/48] merge-recursive: Fix modify/delete resolution in the recursive case

From
Elijah Newren <newren@gmail.com>
Date
Jun 8, 2011, 07:31 UTC
Message-ID
<1307518278-23814-38-git-send-email-newren@gmail.com>
In-Reply-To
<1307518278-23814-1-git-send-email-newren@gmail.com>

When o->call_depth>0 and we have conflicts, we try to find "middle ground" when creating the virtual merge base. In the case of content conflicts, this can be done by doing a three-way content merge and using the result. In all parts where the three-way content merge is clean, it is the correct middle ground, and in parts where it conflicts there is no middle ground but the conflict markers provide a good compromise since they are unlikely to accidentally match any further changes.

In the case of a modify/delete conflict, we cannot do the same thing. Accepting either endpoint as the resolution for the virtual merge base runs the risk that when handling the non-recursive case we will silently accept one person's resolution over another without flagging a conflict. In this case, the closest "middle ground" we have is actually the merge base of the candidate merge bases. (We could alternatively attempt a three way content merge using an empty file in place of the deleted file, but that seems to be more work than necessary.)

Signed-off-by: Elijah Newren <newren@gmail.com>
---
 merge-recursive.c                 |   32 +++++++++++++++++++++-----------
 t/t6036-recursive-corner-cases.sh |    4 ++--
 2 files changed, 23 insertions(+), 13 deletions(-)
diff --git a/merge-recursive.c b/merge-recursive.c
index da507a3..5a70a87 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1309,11 +1309,26 @@ error_return:
 
 static void handle_delete_modify(struct merge_options *o,
 				 const char *path,
-				 const char *new_path,
+				 unsigned char *o_sha, int o_mode,
 				 unsigned char *a_sha, int a_mode,
 				 unsigned char *b_sha, int b_mode)
 {
-	if (!a_sha) {
+	char *new_path = NULL;
+	int free_me = 0;
+	if (dir_in_way(path, !o->call_depth)) {
+		new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
+		free_me = 1;
+	}
+
+	if (o->call_depth) {
+		/*
+		 * We cannot arbitrarily accept either a_sha or b_sha as
+		 * correct; since there is no true "middle point" between
+		 * them, simply reuse the base version for virtual merge base.
+		 */
+		remove_file_from_cache(path);
+		update_file(o, 0, o_sha, o_mode, new_path ? new_path : path);
+	} else if (!a_sha) {
 		output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
 		       "and modified in %s. Version %s of %s left in tree%s%s.",
 		       path, o->branch1,
@@ -1330,6 +1345,9 @@ static void handle_delete_modify(struct merge_options *o,
 		       NULL == new_path ? "" : new_path);
 		update_file(o, 0, a_sha, a_mode, new_path ? new_path : path);
 	}
+	if (free_me)
+		free(new_path);
+
 }
 
 static int merge_content(struct merge_options *o,
@@ -1482,17 +1500,9 @@ static int process_entry(struct merge_options *o,
 			remove_file(o, 1, path, !a_sha);
 		} else {
 			/* Modify/delete; deleted side may have put a directory in the way */
-			char *new_path = NULL;
-			int free_me = 0;
 			clean_merge = 0;
-			if (dir_in_way(path, !o->call_depth)) {
-				new_path = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
-				free_me = 1;
-			}
-			handle_delete_modify(o, path, new_path,
+			handle_delete_modify(o, path, o_sha, o_mode,
 					     a_sha, a_mode, b_sha, b_mode);
-			if (free_me)
-				free(new_path);
 		}
 	} else if ((!o_sha && a_sha && !b_sha) ||
 		   (!o_sha && !a_sha && b_sha)) {
diff --git a/t/t6036-recursive-corner-cases.sh b/t/t6036-recursive-corner-cases.sh
index 8d1d303..d27477b 100755
--- a/t/t6036-recursive-corner-cases.sh
+++ b/t/t6036-recursive-corner-cases.sh
@@ -290,7 +290,7 @@ test_expect_success 'setup criss-cross + modify/delete resolved differently' '
 	git tag E
 '
 
-test_expect_failure 'git detects conflict merging criss-cross+modify/delete' '
+test_expect_success 'git detects conflict merging criss-cross+modify/delete' '
 	git checkout D^0 &&
 
 	test_must_fail git merge -s recursive E^0 &&
@@ -302,7 +302,7 @@ test_expect_failure 'git detects conflict merging criss-cross+modify/delete' '
 	test $(git rev-parse :2:file) = $(git rev-parse B:file)
 '
 
-test_expect_failure 'git detects conflict merging criss-cross+modify/delete, reverse direction' '
+test_expect_success 'git detects conflict merging criss-cross+modify/delete, reverse direction' '
 	git reset --hard &&
 	git checkout E^0 &&
 

-- 
1.7.6.rc0.62.g2d69f
Previous: Junio C HamanoNext: Junio C Hamano
Message 71 of 97 in “Handling more corner cases in merge-recursive.c”
  1. 00/48 Handling more corner cases in merge-recursive.cElijah Newren, Jun 8, 2011
  2. 01/48 t6039: Add a testcase where git deletes an untracked fileElijah Newren, Jun 8, 2011
  3. 02/48 t6039: Add failing testcase for rename/modify/add-source conflictElijah Newren, Jun 8, 2011
  4. 03/48 t6039: Add a pair of cases where undetected renames cause issuesElijah Newren, Jun 8, 2011
  5. 04/48 t6039: Add a testcase where undetected rename causes silent file deletionElijah Newren, Jun 8, 2011
  6. 05/48 t6039: Add tests for content issues with modify/rename/directory conflictsElijah Newren, Jun 8, 2011
  7. Junio C HamanoJul 18, 2011
  8. Elijah NewrenAug 8, 2011
  9. 06/48 t6039: Add failing testcases for rename/rename/add-{source,dest} conflictsElijah Newren, Jun 8, 2011
  10. Junio C HamanoJul 18, 2011
  11. 07/48 t6039: Ensure rename/rename conflicts leave index and workdir in sane stateElijah Newren, Jun 8, 2011
  12. Junio C HamanoJul 18, 2011
  13. Elijah NewrenAug 8, 2011
  14. 08/48 t6036: Add differently resolved modify/delete conflict in criss-cross testElijah Newren, Jun 8, 2011
  15. Junio C HamanoJul 18, 2011
  16. 09/48 t6036: criss-cross with weird content can fool git into clean mergeElijah Newren, Jun 8, 2011
  17. Junio C HamanoJul 18, 2011
  18. Elijah NewrenAug 8, 2011
  19. 10/48 t6036: tests for criss-cross merges with various directory/file conflictsElijah Newren, Jun 8, 2011
  20. Junio C HamanoJul 18, 2011
  21. Elijah NewrenAug 8, 2011
  22. 11/48 t6036: criss-cross w/ rename/rename(1to2)/modify+rename/rename(2to1)/modifyElijah Newren, Jun 8, 2011
  23. Junio C HamanoJul 18, 2011
  24. 12/48 t6036: criss-cross + rename/rename(1to2)/add-source + modify/modifyElijah Newren, Jun 8, 2011
  25. Junio C HamanoJul 18, 2011
  26. Phil HordJul 20, 2011
  27. 13/48 t6022: Remove unnecessary untracked files to make test cleanerElijah Newren, Jun 8, 2011
  28. 14/48 t6022: New tests checking for unnecessary updates of filesElijah Newren, Jun 8, 2011
  29. 15/48 t6022: Add testcase for merging a renamed file with a simple changeElijah Newren, Jun 8, 2011
  30. 16/48 merge-recursive: Make BUG message more legible by adding a newlineElijah Newren, Jun 8, 2011
  31. 17/48 merge-recursive: Correct a commentElijah Newren, Jun 8, 2011
  32. 18/48 merge-recursive: Mark some diff_filespec struct arguments constElijah Newren, Jun 8, 2011
  33. Junio C HamanoJul 18, 2011
  34. 19/48 merge-recursive: Remember to free generated unique path namesElijah Newren, Jun 8, 2011
  35. Junio C HamanoJul 18, 2011
  36. 20/48 merge-recursive: Avoid working directory changes during recursive caseElijah Newren, Jun 8, 2011
  37. 21/48 merge-recursive: Fix recursive case with D/F conflict via add/add conflictElijah Newren, Jun 8, 2011
  38. Junio C HamanoJul 18, 2011
  39. 22/48 merge-recursive: Fix sorting order and directory change assumptionsElijah Newren, Jun 8, 2011
  40. Johannes SixtJul 11, 2011
  41. Johannes SixtJul 12, 2011
  42. Johannes SixtJul 13, 2011
  43. Junio C HamanoJul 13, 2011
  44. Junio C HamanoJul 18, 2011
  45. Elijah NewrenAug 8, 2011
  46. 23/48 merge-recursive: Fix code checking for D/F conflicts still being presentElijah Newren, Jun 8, 2011
  47. 24/48 merge-recursive: Save D/F conflict filenames instead of unlinking themElijah Newren, Jun 8, 2011
  48. 25/48 merge-recursive: Split was_tracked() out of would_lose_untracked()Elijah Newren, Jun 8, 2011
  49. 26/48 merge-recursive: Allow make_room_for_path() to remove D/F entriesElijah Newren, Jun 8, 2011
  50. Johannes SixtJul 11, 2011
  51. Johannes SixtJul 13, 2011
  52. Elijah NewrenAug 8, 2011
  53. Johannes SixtAug 9, 2011
  54. Junio C HamanoJul 18, 2011
  55. 27/48 merge-recursive: Consolidate different update_stages functionsElijah Newren, Jun 8, 2011
  56. Junio C HamanoJul 18, 2011
  57. 28/48 merge-recursive: Split update_stages_and_entry; only update stages at endElijah Newren, Jun 8, 2011
  58. Junio C HamanoJul 18, 2011
  59. 29/48 merge-recursive: When we detect we can skip an update, actually skip itElijah Newren, Jun 8, 2011
  60. Junio C HamanoJul 18, 2011
  61. 30/48 merge-recursive: Fix deletion of untracked file in rename/delete conflictsElijah Newren, Jun 8, 2011
  62. Junio C HamanoJul 21, 2011
  63. 31/48 merge-recursive: Make dead code for rename/rename(2to1) conflicts undeadElijah Newren, Jun 8, 2011
  64. 32/48 merge-recursive: Add comments about handling rename/add-source casesElijah Newren, Jun 8, 2011
  65. 33/48 merge-recursive: Improve handling of rename target vs. directory additionElijah Newren, Jun 8, 2011
  66. 34/48 merge-recursive: Consolidate process_entry() and process_df_entry()Elijah Newren, Jun 8, 2011
  67. Junio C HamanoJul 21, 2011
  68. 35/48 merge-recursive: Cleanup and consolidation of rename_conflict_infoElijah Newren, Jun 8, 2011
  69. 36/48 merge-recursive: Provide more info in conflict markers with file renamesElijah Newren, Jun 8, 2011
  70. Junio C HamanoJul 21, 2011
  71. 37/48 merge-recursive: Fix modify/delete resolution in the recursive caseElijah Newren, Jun 8, 2011
  72. Junio C HamanoJul 21, 2011
  73. Elijah NewrenAug 8, 2011
  74. 38/48 merge-recursive: Introduce a merge_file convenience functionElijah Newren, Jun 8, 2011
  75. 39/48 merge-recursive: Fix rename/rename(1to2) resolution for virtual merge baseElijah Newren, Jun 8, 2011
  76. Junio C HamanoJul 25, 2011
  77. Elijah NewrenAug 8, 2011
  78. 40/48 merge-recursive: Small cleanups for conflict_rename_rename_1to2Elijah Newren, Jun 8, 2011
  79. 41/48 merge-recursive: Defer rename/rename(2to1) handling until process_entryElijah Newren, Jun 8, 2011
  80. 42/48 merge-recursive: Record more data needed for merging with dual renamesElijah Newren, Jun 8, 2011
  81. 43/48 merge-recursive: Create function for merging with branchname:file markersElijah Newren, Jun 8, 2011
  82. 44/48 merge-recursive: Consider modifications in rename/rename(2to1) conflictsElijah Newren, Jun 8, 2011
  83. 45/48 merge-recursive: Make modify/delete handling code reusableElijah Newren, Jun 8, 2011
  84. 46/48 merge-recursive: Have conflict_rename_delete reuse modify/delete codeElijah Newren, Jun 8, 2011
  85. 47/48 merge-recursive: add handling for rename/rename/add-dest/add-destElijah Newren, Jun 8, 2011
  86. 48/48 merge-recursive: Fix working copy handling for rename/rename/add/addElijah Newren, Jun 8, 2011
  87. Junio C HamanoJun 11, 2011
  88. Junio C HamanoAug 4, 2011
  89. Junio C HamanoAug 4, 2011
  90. Elijah NewrenAug 4, 2011
  91. Elijah NewrenAug 4, 2011
  92. Junio C HamanoAug 4, 2011
  93. Elijah NewrenAug 4, 2011
  94. Junio C HamanoAug 6, 2011
  95. Elijah NewrenAug 6, 2011
  96. Junio C HamanoJun 12, 2011
  97. Junio C HamanoJun 12, 2011

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