merge-recursive: internal flag to avoid touching the worktree

o->call_depth has a double function: a nonzero call_depth means we
want to construct virtual merge bases, but it also means we want to
avoid touching the worktree.  Introduce a new flag o->no_worktree to
trigger only the latter.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 22 insertions, 16 deletions

diff --git a/merge-recursive.c b/merge-recursive.c
index 4459607af3..059ad037be 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -410,10 +410,10 @@ static void record_df_conflict_files(struct merge_options *o,
 	int i;
 
 	/*
-	 * If we're merging merge-bases, we don't want to bother with
-	 * any working directory changes.
+	 * If we're working in-core only (e.g., merging merge-bases),
+	 * we don't want to bother with any working directory changes.
 	 */
-	if (o->call_depth)
+	if (o->call_depth || o->no_worktree)
 		return;
 
 	/* Ensure D/F conflicts are adjacent in the entries list. */
@@ -743,7 +743,7 @@ static void update_file_flags(struct merge_options *o,
 			      int update_cache,
 			      int update_wd)
 {
-	if (o->call_depth)
+	if (o->call_depth || o->no_worktree)
 		update_wd = 0;
 
 	if (update_wd) {
@@ -950,7 +950,8 @@ static struct merge_file_info merge_file_1(struct merge_options *o,
 			result.clean = merge_submodule(result.sha,
 						       one->path, one->sha1,
 						       a->sha1, b->sha1,
-						       !o->call_depth);
+						       !(o->call_depth ||
+							 o->no_worktree));
 		} else if (S_ISLNK(a->mode)) {
 			hashcpy(result.sha, a->sha1);
 
@@ -1018,7 +1019,7 @@ static void handle_change_delete(struct merge_options *o,
 				 const char *change, const char *change_past)
 {
 	char *renamed = NULL;
-	if (dir_in_way(path, !o->call_depth)) {
+	if (dir_in_way(path, !(o->call_depth || o->no_worktree))) {
 		renamed = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
 	}
 
@@ -1143,10 +1144,10 @@ static void handle_file(struct merge_options *o,
 		char *add_name = unique_path(o, rename->path, other_branch);
 		update_file(o, 0, add->sha1, add->mode, add_name);
 
-		remove_file(o, 0, rename->path, 0);
+		remove_file(o, 0, rename->path, o->call_depth || o->no_worktree);
 		dst_name = unique_path(o, rename->path, cur_branch);
 	} else {
-		if (dir_in_way(rename->path, !o->call_depth)) {
+		if (dir_in_way(rename->path, !(o->call_depth || o->no_worktree))) {
 			dst_name = unique_path(o, rename->path, cur_branch);
 			output(o, 1, _("%s is a directory in %s adding as %s instead"),
 			       rename->path, other_branch, dst_name);
@@ -1253,7 +1254,7 @@ static void conflict_rename_rename_2to1(struct merge_options *o,
 		 * merge base just undo the renames; they can be detected
 		 * again later for the non-recursive merge.
 		 */
-		remove_file(o, 0, path, 0);
+		remove_file(o, 0, path, o->call_depth || o->no_worktree);
 		update_file(o, 0, mfi_c1.sha, mfi_c1.mode, a->path);
 		update_file(o, 0, mfi_c2.sha, mfi_c2.mode, b->path);
 	} else {
@@ -1261,7 +1262,7 @@ static void conflict_rename_rename_2to1(struct merge_options *o,
 		char *new_path2 = unique_path(o, path, ci->branch2);
 		output(o, 1, _("Renaming %s to %s and %s to %s instead"),
 		       a->path, new_path1, b->path, new_path2);
-		remove_file(o, 0, path, 0);
+		remove_file(o, 0, path, o->call_depth || o->no_worktree);
 		update_file(o, 0, mfi_c1.sha, mfi_c1.mode, new_path1);
 		update_file(o, 0, mfi_c2.sha, mfi_c2.mode, new_path2);
 		free(new_path2);
@@ -1420,6 +1421,7 @@ static int process_renames(struct merge_options *o,
 			 * add-source case).
 			 */
 			remove_file(o, 1, ren1_src,
+				    o->call_depth || o->no_worktree ||
 				    renamed_stage == 2 || !was_tracked(ren1_src));
 
 			hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);
@@ -1616,7 +1618,7 @@ static int merge_content(struct merge_options *o,
 			 o->branch2 == rename_conflict_info->branch1) ?
 			pair1->two->path : pair1->one->path;
 
-		if (dir_in_way(path, !o->call_depth))
+		if (dir_in_way(path, !(o->call_depth || o->no_worktree)))
 			df_conflict_remains = 1;
 	}
 	mfi = merge_file_special_markers(o, &one, &a, &b,
@@ -1636,7 +1638,7 @@ static int merge_content(struct merge_options *o,
 		path_renamed_outside_HEAD = !path2 || !strcmp(path, path2);
 		if (!path_renamed_outside_HEAD) {
 			add_cacheinfo(mfi.mode, mfi.sha, path,
-				      0, (!o->call_depth), 0);
+				      0, !(o->call_depth || o->no_worktree), 0);
 			return mfi.clean;
 		}
 	} else
@@ -1737,7 +1739,8 @@ static int process_entry(struct merge_options *o,
 			if (a_sha)
 				output(o, 2, _("Removing %s"), path);
 			/* do not touch working file if it did not exist */
-			remove_file(o, 1, path, !a_sha);
+			remove_file(o, 1, path,
+				    o->call_depth || o->no_worktree || !a_sha);
 		} else {
 			/* Modify/delete; deleted side may have put a directory in the way */
 			clean_merge = 0;
@@ -1768,7 +1771,7 @@ static int process_entry(struct merge_options *o,
 			sha = b_sha;
 			conf = _("directory/file");
 		}
-		if (dir_in_way(path, !o->call_depth)) {
+		if (dir_in_way(path, !(o->call_depth || o->no_worktree))) {
 			char *new_path = unique_path(o, path, add_branch);
 			clean_merge = 0;
 			output(o, 1, _("CONFLICT (%s): There is a directory with name %s in %s. "
@@ -1796,7 +1799,8 @@ static int process_entry(struct merge_options *o,
 		 * this entry was deleted altogether. a_mode == 0 means
 		 * we had that path and want to actively remove it.
 		 */
-		remove_file(o, 1, path, !a_mode);
+		remove_file(o, 1, path,
+			    o->call_depth || o->no_worktree || !a_mode);
 	} else
 		die(_("Fatal merge failure, shouldn't happen."));
 
@@ -1822,7 +1826,8 @@ int merge_trees(struct merge_options *o,
 		return 1;
 	}
 
-	code = git_merge_trees(o->call_depth, common, head, merge);
+	code = git_merge_trees(o->call_depth || o->no_worktree,
+			       common, head, merge);
 
 	if (code != 0) {
 		if (show(o, 4) || o->call_depth)
diff --git a/merge-recursive.h b/merge-recursive.h
index 9e090a3470..d8dd7a1211 100644
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -15,6 +15,7 @@ struct merge_options {
 	const char *subtree_shift;
 	unsigned buffer_output : 1;
 	unsigned renormalize : 1;
+	unsigned no_worktree : 1; /* do not touch worktree */
 	long xdl_opts;
 	int verbosity;
 	int diff_rename_limit;