merge_file should use more aggressive levels

The default merge_file level was XDL_MERGE_MINIMAL, which will
produce conflicts where there should not be in the case where
both sides were changed identically.  Change the defaults to be
more aggressive (XDL_MERGE_ZEALOUS) which will more aggressively
compress non-conflicts.  This matches git.git's defaults.

Increase testing around reverting a previously reverted commit to
illustrate this problem.

1 files changed, 10 insertions, 7 deletions

diff --git a/src/merge.c b/src/merge.c
index c0be37dd8..3ac9167e3 100644
--- a/src/merge.c
+++ b/src/merge.c
@@ -511,8 +511,9 @@ static int merge_conflict_resolve_automerge(
 	int *resolved,
 	git_merge_diff_list *diff_list,
 	const git_merge_diff *conflict,
-	unsigned int automerge_flags)
+	unsigned int merge_file_favor)
 {
+	git_merge_file_options merge_file_opts = GIT_MERGE_FILE_OPTIONS_INIT;
 	git_merge_file_input ancestor = GIT_MERGE_FILE_INPUT_INIT,
 		ours = GIT_MERGE_FILE_INPUT_INIT,
 		theirs = GIT_MERGE_FILE_INPUT_INIT;
@@ -526,9 +527,11 @@ static int merge_conflict_resolve_automerge(
 
 	*resolved = 0;
 
-	if (automerge_flags == GIT_MERGE_AUTOMERGE_NONE)
+	if (merge_file_favor == GIT_MERGE_FILE_FAVOR_NO_MERGE)
 		return 0;
 
+	merge_file_opts.favor = merge_file_favor;
+
 	/* Reject D/F conflicts */
 	if (conflict->type == GIT_MERGE_DIFF_DIRECTORY_FILE)
 		return 0;
@@ -552,7 +555,7 @@ static int merge_conflict_resolve_automerge(
 		(error = git_merge_file_input_from_index_entry(&ancestor, diff_list->repo, &conflict->ancestor_entry)) < 0 ||
 		(error = git_merge_file_input_from_index_entry(&ours, diff_list->repo, &conflict->our_entry)) < 0 ||
 		(error = git_merge_file_input_from_index_entry(&theirs, diff_list->repo, &conflict->their_entry)) < 0 ||
-		(error = git_merge_files(&result, &ancestor, &ours, &theirs, automerge_flags)) < 0 ||
+		(error = git_merge_files(&result, &ancestor, &ours, &theirs, &merge_file_opts)) < 0 ||
 		!result.automergeable ||
 		(error = git_odb_write(&automerge_oid, odb, result.data, result.len, GIT_OBJ_BLOB)) < 0)
 		goto done;
@@ -586,7 +589,7 @@ static int merge_conflict_resolve(
 	int *out,
 	git_merge_diff_list *diff_list,
 	const git_merge_diff *conflict,
-	unsigned int automerge_flags)
+	unsigned int merge_file_favor)
 {
 	int resolved = 0;
 	int error = 0;
@@ -596,14 +599,14 @@ static int merge_conflict_resolve(
 	if ((error = merge_conflict_resolve_trivial(&resolved, diff_list, conflict)) < 0)
 		goto done;
 
-	if (automerge_flags != GIT_MERGE_AUTOMERGE_NONE) {
+	if (merge_file_favor != GIT_MERGE_FILE_FAVOR_NO_MERGE) {
 		if (!resolved && (error = merge_conflict_resolve_one_removed(&resolved, diff_list, conflict)) < 0)
 			goto done;
 
 		if (!resolved && (error = merge_conflict_resolve_one_renamed(&resolved, diff_list, conflict)) < 0)
 			goto done;
 
-		if (!resolved && (error = merge_conflict_resolve_automerge(&resolved, diff_list, conflict, automerge_flags)) < 0)
+		if (!resolved && (error = merge_conflict_resolve_automerge(&resolved, diff_list, conflict, merge_file_favor)) < 0)
 			goto done;
 	}
 
@@ -1589,7 +1592,7 @@ int git_merge_trees(
 	git_vector_foreach(&changes, i, conflict) {
 		int resolved = 0;
 
-		if ((error = merge_conflict_resolve(&resolved, diff_list, conflict, opts.automerge_flags)) < 0)
+		if ((error = merge_conflict_resolve(&resolved, diff_list, conflict, opts.file_favor)) < 0)
 			goto done;
 
 		if (!resolved)