conflicts: when adding conflicts, remove staged

When adding a conflict for some path, remove the staged entry.
Otherwise, an illegal index (with both stage 0 and high-stage
entries) would result.

CHANGELOG.md

@@ -49,6 +49,8 @@ support for HTTPS connections insead of OpenSSL.
   the error message, which allows you to get the "repository not
   found" messages.
 
+* `git_index_conflict_add()` will remove staged entries that exist for
+  conflicted paths.
 
 ### API additions
 

include/git2/index.h

@@ -631,7 +631,8 @@ GIT_EXTERN(int) git_index_find(size_t *at_pos, git_index *index, const char *pat
 /**@{*/
 
 /**
- * Add or update index entries to represent a conflict
+ * Add or update index entries to represent a conflict.  Any staged
+ * entries that exist at the given paths will be removed.
  *
  * The entries are the entries from the tree included in the merge.  Any
  * entry may be null to indicate that that file was not present in the

src/index.c

@@ -1314,6 +1314,21 @@ int git_index_conflict_add(git_index *index,
 		(ret = index_entry_dup(&entries[2], INDEX_OWNER(index), their_entry)) < 0)
 		goto on_error;
 
+	/* Remove existing index entries for each path */
+	for (i = 0; i < 3; i++) {
+		if (entries[i] == NULL)
+			continue;
+
+		if ((ret = git_index_remove(index, entries[i]->path, 0)) != 0) {
+			if (ret != GIT_ENOTFOUND)
+				goto on_error;
+
+			giterr_clear();
+			ret = 0;
+		}
+	}
+
+	/* Add the conflict entries */
 	for (i = 0; i < 3; i++) {
 		if (entries[i] == NULL)
 			continue;
@@ -1321,7 +1336,7 @@ int git_index_conflict_add(git_index *index,
 		/* Make sure stage is correct */
 		GIT_IDXENTRY_STAGE_SET(entries[i], i + 1);
 
-		if ((ret = index_insert(index, &entries[i], 1, true)) < 0)
+		if ((ret = index_insert(index, &entries[i], 0, true)) < 0)
 			goto on_error;
 
 		entries[i] = NULL; /* don't free if later entry fails */

tests/index/conflicts.c

@@ -16,6 +16,7 @@ static git_index *repo_index;
 #define CONFLICTS_TWO_OUR_OID "8b3f43d2402825c200f835ca1762413e386fd0b2"
 #define CONFLICTS_TWO_THEIR_OID "220bd62631c8cf7a83ef39c6b94595f00517211e"
 
+#define TEST_STAGED_OID "beefdadafeedabedcafedeedbabedeadbeaddeaf"
 #define TEST_ANCESTOR_OID "f00ff00ff00ff00ff00ff00ff00ff00ff00ff00f"
 #define TEST_OUR_OID "b44bb44bb44bb44bb44bb44bb44bb44bb44bb44b"
 #define TEST_THEIR_OID "0123456789abcdef0123456789abcdef01234567"
@@ -96,6 +97,55 @@ void test_index_conflicts__add_fixes_incorrect_stage(void)
 	cl_assert(git_index_entry_stage(conflict_entry[2]) == 3);
 }
 
+void test_index_conflicts__add_removes_stage_zero(void)
+{
+	git_index_entry staged, ancestor_entry, our_entry, their_entry;
+	const git_index_entry *conflict_entry[3];
+
+	cl_assert(git_index_entrycount(repo_index) == 8);
+
+	memset(&staged, 0x0, sizeof(git_index_entry));
+	memset(&ancestor_entry, 0x0, sizeof(git_index_entry));
+	memset(&our_entry, 0x0, sizeof(git_index_entry));
+	memset(&their_entry, 0x0, sizeof(git_index_entry));
+
+	staged.mode = 0100644;
+	staged.path = "test-one.txt";
+	git_oid_fromstr(&staged.id, TEST_STAGED_OID);
+	cl_git_pass(git_index_add(repo_index, &staged));
+	cl_assert(git_index_entrycount(repo_index) == 9);
+
+	ancestor_entry.path = "test-one.txt";
+	ancestor_entry.mode = 0100644;
+	ancestor_entry.flags |= (3 << GIT_IDXENTRY_STAGESHIFT);
+	git_oid_fromstr(&ancestor_entry.id, TEST_ANCESTOR_OID);
+
+	our_entry.path = "test-one.txt";
+	our_entry.mode = 0100644;
+	our_entry.flags |= (1 << GIT_IDXENTRY_STAGESHIFT);
+	git_oid_fromstr(&our_entry.id, TEST_OUR_OID);
+
+	their_entry.path = "test-one.txt";
+	their_entry.mode = 0100644;
+	their_entry.flags |= (2 << GIT_IDXENTRY_STAGESHIFT);
+	git_oid_fromstr(&their_entry.id, TEST_THEIR_OID);
+
+	cl_git_pass(git_index_conflict_add(repo_index, &ancestor_entry, &our_entry, &their_entry));
+
+	cl_assert(git_index_entrycount(repo_index) == 11);
+
+	cl_assert_equal_p(NULL, git_index_get_bypath(repo_index, "test-one.txt", 0));
+
+	cl_git_pass(git_index_conflict_get(&conflict_entry[0], &conflict_entry[1], &conflict_entry[2], repo_index, "test-one.txt"));
+
+	cl_assert_equal_oid(&ancestor_entry.id, &conflict_entry[0]->id);
+	cl_assert_equal_i(1, git_index_entry_stage(conflict_entry[0]));
+	cl_assert_equal_oid(&our_entry.id, &conflict_entry[1]->id);
+	cl_assert_equal_i(2, git_index_entry_stage(conflict_entry[1]));
+	cl_assert_equal_oid(&their_entry.id, &conflict_entry[2]->id);
+	cl_assert_equal_i(3, git_index_entry_stage(conflict_entry[2]));
+}
+
 void test_index_conflicts__get(void)
 {
 	const git_index_entry *conflict_entry[3];

tests/status/worktree.c

@@ -634,7 +634,7 @@ void test_status_worktree__conflicted_item(void)
 		&our_entry, &their_entry));
 
 	cl_git_pass(git_status_file(&status, repo, "modified_file"));
-	cl_assert_equal_i(GIT_STATUS_WT_MODIFIED, status);
+	cl_assert_equal_i(GIT_STATUS_INDEX_DELETED|GIT_STATUS_WT_NEW, status);
 
 	git_index_free(index);
 }