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[PATCH v7 20/31] merge-recursive: check for directory level conflicts

From
Elijah Newren <newren@gmail.com>
Date
Jan 30, 2018, 23:25 UTC
Message-ID
<20180130232533.25846-21-newren@gmail.com>
In-Reply-To
<20180130232533.25846-1-newren@gmail.com>

Before trying to apply directory renames to paths within the given directories, we want to make sure that there aren't conflicts at the directory level. There will be additional checks at the individual file level too, which will be added later.

Signed-off-by: Elijah Newren <newren@gmail.com>
---
 merge-recursive.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 119 insertions(+)
diff --git a/merge-recursive.c b/merge-recursive.c
index c75d3a5139..9e9ad45d2a 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1393,6 +1393,15 @@ static struct diff_queue_struct *get_diffpairs(struct merge_options *o,
 	return ret;
 }
 
+static int tree_has_path(struct tree *tree, const char *path)
+{
+	unsigned char hashy[20];
+	unsigned int mode_o;
+
+	return !get_tree_entry(tree->object.oid.hash, path,
+			       hashy, &mode_o);
+}
+
 static void get_renamed_dir_portion(const char *old_path, const char *new_path,
 				    char **old_dir, char **new_dir)
 {
@@ -1447,6 +1456,112 @@ static void get_renamed_dir_portion(const char *old_path, const char *new_path,
 	}
 }
 
+static void remove_hashmap_entries(struct hashmap *dir_renames,
+				   struct string_list *items_to_remove)
+{
+	int i;
+	struct dir_rename_entry *entry;
+
+	for (i = 0; i < items_to_remove->nr; i++) {
+		entry = items_to_remove->items[i].util;
+		hashmap_remove(dir_renames, entry, NULL);
+	}
+	string_list_clear(items_to_remove, 0);
+}
+
+/*
+ * There are a couple things we want to do at the directory level:
+ *   1. Check for both sides renaming to the same thing, in order to avoid
+ *      implicit renaming of files that should be left in place.  (See
+ *      testcase 6b in t6043 for details.)
+ *   2. Prune directory renames if there are still files left in the
+ *      the original directory.  These represent a partial directory rename,
+ *      i.e. a rename where only some of the files within the directory
+ *      were renamed elsewhere.  (Technically, this could be done earlier
+ *      in get_directory_renames(), except that would prevent us from
+ *      doing the previous check and thus failing testcase 6b.)
+ *   3. Check for rename/rename(1to2) conflicts (at the directory level).
+ *      In the future, we could potentially record this info as well and
+ *      omit reporting rename/rename(1to2) conflicts for each path within
+ *      the affected directories, thus cleaning up the merge output.
+ *   NOTE: We do NOT check for rename/rename(2to1) conflicts at the
+ *         directory level, because merging directories is fine.  If it
+ *         causes conflicts for files within those merged directories, then
+ *         that should be detected at the individual path level.
+ */
+static void handle_directory_level_conflicts(struct merge_options *o,
+					     struct hashmap *dir_re_head,
+					     struct tree *head,
+					     struct hashmap *dir_re_merge,
+					     struct tree *merge)
+{
+	struct hashmap_iter iter;
+	struct dir_rename_entry *head_ent;
+	struct dir_rename_entry *merge_ent;
+
+	struct string_list remove_from_head = STRING_LIST_INIT_NODUP;
+	struct string_list remove_from_merge = STRING_LIST_INIT_NODUP;
+
+	hashmap_iter_init(dir_re_head, &iter);
+	while ((head_ent = hashmap_iter_next(&iter))) {
+		merge_ent = dir_rename_find_entry(dir_re_merge, head_ent->dir);
+		if (merge_ent &&
+		    !head_ent->non_unique_new_dir &&
+		    !merge_ent->non_unique_new_dir &&
+		    !strbuf_cmp(&head_ent->new_dir, &merge_ent->new_dir)) {
+			/* 1. Renamed identically; remove it from both sides */
+			string_list_append(&remove_from_head,
+					   head_ent->dir)->util = head_ent;
+			strbuf_release(&head_ent->new_dir);
+			string_list_append(&remove_from_merge,
+					   merge_ent->dir)->util = merge_ent;
+			strbuf_release(&merge_ent->new_dir);
+		} else if (tree_has_path(head, head_ent->dir)) {
+			/* 2. This wasn't a directory rename after all */
+			string_list_append(&remove_from_head,
+					   head_ent->dir)->util = head_ent;
+			strbuf_release(&head_ent->new_dir);
+		}
+	}
+
+	remove_hashmap_entries(dir_re_head, &remove_from_head);
+	remove_hashmap_entries(dir_re_merge, &remove_from_merge);
+
+	hashmap_iter_init(dir_re_merge, &iter);
+	while ((merge_ent = hashmap_iter_next(&iter))) {
+		head_ent = dir_rename_find_entry(dir_re_head, merge_ent->dir);
+		if (tree_has_path(merge, merge_ent->dir)) {
+			/* 2. This wasn't a directory rename after all */
+			string_list_append(&remove_from_merge,
+					   merge_ent->dir)->util = merge_ent;
+		} else if (head_ent &&
+			   !head_ent->non_unique_new_dir &&
+			   !merge_ent->non_unique_new_dir) {
+			/* 3. rename/rename(1to2) */
+			/*
+			 * We can assume it's not rename/rename(1to1) because
+			 * that was case (1), already checked above.  So we
+			 * know that head_ent->new_dir and merge_ent->new_dir
+			 * are different strings.
+			 */
+			output(o, 1, _("CONFLICT (rename/rename): "
+				       "Rename directory %s->%s in %s. "
+				       "Rename directory %s->%s in %s"),
+			       head_ent->dir, head_ent->new_dir.buf, o->branch1,
+			       head_ent->dir, merge_ent->new_dir.buf, o->branch2);
+			string_list_append(&remove_from_head,
+					   head_ent->dir)->util = head_ent;
+			strbuf_release(&head_ent->new_dir);
+			string_list_append(&remove_from_merge,
+					   merge_ent->dir)->util = merge_ent;
+			strbuf_release(&merge_ent->new_dir);
+		}
+	}
+
+	remove_hashmap_entries(dir_re_head, &remove_from_head);
+	remove_hashmap_entries(dir_re_merge, &remove_from_merge);
+}
+
 static struct hashmap *get_directory_renames(struct diff_queue_struct *pairs,
 					     struct tree *tree)
 {
@@ -1878,6 +1993,10 @@ static int handle_renames(struct merge_options *o,
 	dir_re_head = get_directory_renames(head_pairs, head);
 	dir_re_merge = get_directory_renames(merge_pairs, merge);
 
+	handle_directory_level_conflicts(o,
+					 dir_re_head, head,
+					 dir_re_merge, merge);
+
 	ri->head_renames  = get_renames(o, head_pairs, head,
 					 common, head, merge, entries);
 	ri->merge_renames = get_renames(o, merge_pairs, merge,

-- 
2.16.1.106.gf69932adfe
Previous: Stefan BellerNext: Stefan Beller
Message 23 of 63 in “Add directory rename detection to git”
  1. 00/31 Add directory rename detection to gitElijah Newren, Jan 30, 2018
  2. Elijah NewrenJan 30, 2018
  3. 24/31 merge-recursive: when comparing files, don't include treesElijah Newren, Jan 30, 2018
  4. 28/31 merge-recursive: fix remaining directory rename + dirty overwrite casesElijah Newren, Jan 30, 2018
  5. Stefan BellerFeb 5, 2018
  6. Elijah NewrenFeb 5, 2018
  7. 05/31 directory rename detection: files/directories in the way of some renamesElijah Newren, Jan 30, 2018
  8. 06/31 directory rename detection: testcases checking which side did the renameElijah Newren, Jan 30, 2018
  9. 10/31 directory rename detection: tests for handling overwriting untracked filesElijah Newren, Jan 30, 2018
  10. 15/31 merge-recursive: make !o->detect_rename codepath more obviousElijah Newren, Jan 30, 2018
  11. Stefan BellerFeb 2, 2018
  12. 14/31 merge-recursive: fix leaks of allocated renames and diff_filepairsElijah Newren, Jan 30, 2018
  13. Stefan BellerFeb 2, 2018
  14. 23/31 merge-recursive: check for file level conflicts then get new nameElijah Newren, Jan 30, 2018
  15. 30/31 merge-recursive: avoid spurious rename/rename conflict from dir renamesElijah Newren, Jan 30, 2018
  16. 16/31 merge-recursive: split out code for determining diff_filepairsElijah Newren, Jan 30, 2018
  17. Stefan BellerFeb 3, 2018
  18. Elijah NewrenFeb 3, 2018
  19. 11/31 directory rename detection: tests for handling overwriting dirty filesElijah Newren, Jan 30, 2018
  20. 22/31 merge-recursive: add computation of collisions due to dir rename & mergingElijah Newren, Jan 30, 2018
  21. 31/31 merge-recursive: ensure we write updates for directory-renamed fileElijah Newren, Jan 30, 2018
  22. Stefan BellerFeb 5, 2018
  23. 20/31 merge-recursive: check for directory level conflictsElijah Newren, Jan 30, 2018
  24. Stefan BellerFeb 5, 2018
  25. Elijah NewrenFeb 5, 2018
  26. 25/31 merge-recursive: apply necessary modifications for directory renamesElijah Newren, Jan 30, 2018
  27. SZEDER GáborFeb 16, 2018
  28. 17/31 merge-recursive: add a new hashmap for storing directory renamesElijah Newren, Jan 30, 2018
  29. Stefan BellerFeb 3, 2018
  30. Elijah NewrenFeb 3, 2018
  31. Johannes SixtFeb 4, 2018
  32. Elijah NewrenFeb 5, 2018
  33. Junio C HamanoFeb 5, 2018
  34. Stefan BellerFeb 5, 2018
  35. Elijah NewrenFeb 5, 2018
  36. 21/31 merge-recursive: add a new hashmap for storing file collisionsElijah Newren, Jan 30, 2018
  37. Stefan BellerFeb 5, 2018
  38. 29/31 directory rename detection: new testcases showcasing a pair of bugsElijah Newren, Jan 30, 2018
  39. 27/31 merge-recursive: fix overwriting dirty files involved in renamesElijah Newren, Jan 30, 2018
  40. Stefan BellerFeb 5, 2018
  41. Elijah NewrenFeb 5, 2018
  42. 03/31 directory rename detection: testcases to avoid taking detection too farElijah Newren, Jan 30, 2018
  43. 01/31 directory rename detection: basic testcasesElijah Newren, Jan 30, 2018
  44. 04/31 directory rename detection: partially renamed directory testcase/discussionElijah Newren, Jan 30, 2018
  45. 19/31 merge-recursive: add get_directory_renames()Elijah Newren, Jan 30, 2018
  46. Stefan BellerFeb 3, 2018
  47. Elijah NewrenFeb 3, 2018
  48. Elijah NewrenFeb 4, 2018
  49. Eric SunshineFeb 4, 2018
  50. Eric SunshineFeb 4, 2018
  51. Stefan BellerFeb 5, 2018
  52. 18/31 merge-recursive: make a helper function for cleanup for handle_renamesElijah Newren, Jan 30, 2018
  53. Stefan BellerFeb 3, 2018
  54. 02/31 directory rename detection: directory splitting testcasesElijah Newren, Jan 30, 2018
  55. 13/31 merge-recursive: introduce new functions to handle rename logicElijah Newren, Jan 30, 2018
  56. Stefan BellerFeb 2, 2018
  57. 12/31 merge-recursive: move the get_renames() functionElijah Newren, Jan 30, 2018
  58. Stefan BellerFeb 2, 2018
  59. 09/31 directory rename detection: miscellaneous testcases to complete coverageElijah Newren, Jan 30, 2018
  60. 08/31 directory rename detection: testcases exploring possibly suboptimal mergesElijah Newren, Jan 30, 2018
  61. 26/31 merge-recursive: avoid clobbering untracked files with directory renamesElijah Newren, Jan 30, 2018
  62. 07/31 directory rename detection: more involved edge/corner testcasesElijah Newren, Jan 30, 2018
  63. Stefan BellerFeb 5, 2018

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