fast-import: allow moving the root treejk/fast-import-empty-ls

Because fast-import.c::tree_content_remove does not check for the empty
path, it is not possible to move the root tree to a subdirectory.
Instead the error "Path  not in branch" is produced (note the double
space where the empty path has been inserted).

Fix this by explicitly checking for the empty path and handling it.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 14 insertions, 7 deletions

diff --git a/fast-import.c b/fast-import.c
index 5da07e83e5..1b9a4359c8 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -1568,7 +1568,8 @@ static int tree_content_set(
 static int tree_content_remove(
 	struct tree_entry *root,
 	const char *p,
-	struct tree_entry *backup_leaf)
+	struct tree_entry *backup_leaf,
+	int allow_root)
 {
 	struct tree_content *t;
 	const char *slash1;
@@ -1583,6 +1584,12 @@ static int tree_content_remove(
 
 	if (!root->tree)
 		load_tree(root);
+
+	if (!*p && allow_root) {
+		e = root;
+		goto del_entry;
+	}
+
 	t = root->tree;
 	for (i = 0; i < t->entry_count; i++) {
 		e = t->entries[i];
@@ -1599,7 +1606,7 @@ static int tree_content_remove(
 				goto del_entry;
 			if (!e->tree)
 				load_tree(e);
-			if (tree_content_remove(e, slash1 + 1, backup_leaf)) {
+			if (tree_content_remove(e, slash1 + 1, backup_leaf, 0)) {
 				for (n = 0; n < e->tree->entry_count; n++) {
 					if (e->tree->entries[n]->versions[1].mode) {
 						hashclr(root->versions[1].sha1);
@@ -2188,7 +2195,7 @@ static uintmax_t do_change_note_fanout(
 			}
 
 			/* Rename fullpath to realpath */
-			if (!tree_content_remove(orig_root, fullpath, &leaf))
+			if (!tree_content_remove(orig_root, fullpath, &leaf, 0))
 				die("Failed to remove path %s", fullpath);
 			tree_content_set(orig_root, realpath,
 				leaf.versions[1].sha1,
@@ -2323,7 +2330,7 @@ static void file_change_m(struct branch *b)
 
 	/* Git does not track empty, non-toplevel directories. */
 	if (S_ISDIR(mode) && !memcmp(sha1, EMPTY_TREE_SHA1_BIN, 20) && *p) {
-		tree_content_remove(&b->branch_tree, p, NULL);
+		tree_content_remove(&b->branch_tree, p, NULL, 0);
 		return;
 	}
 
@@ -2384,7 +2391,7 @@ static void file_change_d(struct branch *b)
 			die("Garbage after path in: %s", command_buf.buf);
 		p = uq.buf;
 	}
-	tree_content_remove(&b->branch_tree, p, NULL);
+	tree_content_remove(&b->branch_tree, p, NULL, 1);
 }
 
 static void file_change_cr(struct branch *b, int rename)
@@ -2422,7 +2429,7 @@ static void file_change_cr(struct branch *b, int rename)
 
 	memset(&leaf, 0, sizeof(leaf));
 	if (rename)
-		tree_content_remove(&b->branch_tree, s, &leaf);
+		tree_content_remove(&b->branch_tree, s, &leaf, 1);
 	else
 		tree_content_get(&b->branch_tree, s, &leaf, 1);
 	if (!leaf.versions[1].mode)
@@ -2530,7 +2537,7 @@ static void note_change_n(struct branch *b, unsigned char *old_fanout)
 	}
 
 	construct_path_with_fanout(sha1_to_hex(commit_sha1), *old_fanout, path);
-	if (tree_content_remove(&b->branch_tree, path, NULL))
+	if (tree_content_remove(&b->branch_tree, path, NULL, 0))
 		b->num_notes--;
 
 	if (is_null_sha1(sha1))