[PATCH v3 19/20] merge-ort: add implementation of record_conflicted_index_entries()

From

Elijah Newren via GitGitGadget <gitgitgadget@gmail.com>

Date

Dec 13, 2020, 08:04 UTC

Message-ID

<ee831c8cece2f6c8a784ed415103f73175f07987.1607846667.git.gitgitgadget@gmail.com>

In-Reply-To

<pull.923.v3.git.git.1607846667.gitgitgadget@gmail.com>

From: Elijah Newren <newren@gmail.com>

Signed-off-by: Elijah Newren <newren@gmail.com>
---
 merge-ort.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 87 insertions(+), 1 deletion(-)

diff --git a/merge-ort.c b/merge-ort.c
index 3c4f64e2675..47cd772e805 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -17,6 +17,7 @@
 #include "cache.h"
 #include "merge-ort.h"
 
+#include "cache-tree.h"
 #include "diff.h"
 #include "diffcore.h"
 #include "dir.h"
@@ -1026,10 +1027,95 @@ static int record_conflicted_index_entries(struct merge_options *opt,
 					   struct strmap *paths,
 					   struct strmap *conflicted)
 {
+	struct hashmap_iter iter;
+	struct strmap_entry *e;
+	int errs = 0;
+	int original_cache_nr;
+
 	if (strmap_empty(conflicted))
 		return 0;
 
-	die("Not yet implemented.");
+	original_cache_nr = index->cache_nr;
+
+	/* Put every entry from paths into plist, then sort */
+	strmap_for_each_entry(conflicted, &iter, e) {
+		const char *path = e->key;
+		struct conflict_info *ci = e->value;
+		int pos;
+		struct cache_entry *ce;
+		int i;
+
+		VERIFY_CI(ci);
+
+		/*
+		 * The index will already have a stage=0 entry for this path,
+		 * because we created an as-merged-as-possible version of the
+		 * file and checkout() moved the working copy and index over
+		 * to that version.
+		 *
+		 * However, previous iterations through this loop will have
+		 * added unstaged entries to the end of the cache which
+		 * ignore the standard alphabetical ordering of cache
+		 * entries and break invariants needed for index_name_pos()
+		 * to work.  However, we know the entry we want is before
+		 * those appended cache entries, so do a temporary swap on
+		 * cache_nr to only look through entries of interest.
+		 */
+		SWAP(index->cache_nr, original_cache_nr);
+		pos = index_name_pos(index, path, strlen(path));
+		SWAP(index->cache_nr, original_cache_nr);
+		if (pos < 0) {
+			if (ci->filemask != 1)
+				BUG("Conflicted %s but nothing in basic working tree or index; this shouldn't happen", path);
+			cache_tree_invalidate_path(index, path);
+		} else {
+			ce = index->cache[pos];
+
+			/*
+			 * Clean paths with CE_SKIP_WORKTREE set will not be
+			 * written to the working tree by the unpack_trees()
+			 * call in checkout().  Our conflicted entries would
+			 * have appeared clean to that code since we ignored
+			 * the higher order stages.  Thus, we need override
+			 * the CE_SKIP_WORKTREE bit and manually write those
+			 * files to the working disk here.
+			 *
+			 * TODO: Implement this CE_SKIP_WORKTREE fixup.
+			 */
+
+			/*
+			 * Mark this cache entry for removal and instead add
+			 * new stage>0 entries corresponding to the
+			 * conflicts.  If there are many conflicted entries, we
+			 * want to avoid memmove'ing O(NM) entries by
+			 * inserting the new entries one at a time.  So,
+			 * instead, we just add the new cache entries to the
+			 * end (ignoring normal index requirements on sort
+			 * order) and sort the index once we're all done.
+			 */
+			ce->ce_flags |= CE_REMOVE;
+		}
+
+		for (i = MERGE_BASE; i <= MERGE_SIDE2; i++) {
+			struct version_info *vi;
+			if (!(ci->filemask & (1ul << i)))
+				continue;
+			vi = &ci->stages[i];
+			ce = make_cache_entry(index, vi->mode, &vi->oid,
+					      path, i+1, 0);
+			add_index_entry(index, ce, ADD_CACHE_JUST_APPEND);
+		}
+	}
+
+	/*
+	 * Remove the unused cache entries (and invalidate the relevant
+	 * cache-trees), then sort the index entries to get the conflicted
+	 * entries we added to the end into their right locations.
+	 */
+	remove_marked_cache_entries(index, 1);
+	QSORT(index->cache, index->cache_nr, cmp_cache_name_compare);
+
+	return errs;
 }
 
 void merge_switch_to_result(struct merge_options *opt,

-- 
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