Merge branch 'jk/fast-import-empty-ls'

* jk/fast-import-empty-ls:
  fast-import: allow moving the root tree
  fast-import: allow ls or filecopy of the root tree
  fast-import: set valid mode on root tree in "ls"
  t9300: document fast-import empty path issues

2 files changed, 103 insertions, 20 deletions

diff --git a/fast-import.c b/fast-import.c
index 23f625f561..21db3fc46d 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);
@@ -1629,7 +1636,8 @@ del_entry:
 static int tree_content_get(
 	struct tree_entry *root,
 	const char *p,
-	struct tree_entry *leaf)
+	struct tree_entry *leaf,
+	int allow_root)
 {
 	struct tree_content *t;
 	const char *slash1;
@@ -1641,31 +1649,39 @@ static int tree_content_get(
 		n = slash1 - p;
 	else
 		n = strlen(p);
-	if (!n)
+	if (!n && !allow_root)
 		die("Empty path component found in input");
 
 	if (!root->tree)
 		load_tree(root);
+
+	if (!n) {
+		e = root;
+		goto found_entry;
+	}
+
 	t = root->tree;
 	for (i = 0; i < t->entry_count; i++) {
 		e = t->entries[i];
 		if (e->name->str_len == n && !strncmp_icase(p, e->name->str_dat, n)) {
-			if (!slash1) {
-				memcpy(leaf, e, sizeof(*leaf));
-				if (e->tree && is_null_sha1(e->versions[1].sha1))
-					leaf->tree = dup_tree_content(e->tree);
-				else
-					leaf->tree = NULL;
-				return 1;
-			}
+			if (!slash1)
+				goto found_entry;
 			if (!S_ISDIR(e->versions[1].mode))
 				return 0;
 			if (!e->tree)
 				load_tree(e);
-			return tree_content_get(e, slash1 + 1, leaf);
+			return tree_content_get(e, slash1 + 1, leaf, 0);
 		}
 	}
 	return 0;
+
+found_entry:
+	memcpy(leaf, e, sizeof(*leaf));
+	if (e->tree && is_null_sha1(e->versions[1].sha1))
+		leaf->tree = dup_tree_content(e->tree);
+	else
+		leaf->tree = NULL;
+	return 1;
 }
 
 static int update_branch(struct branch *b)
@@ -2179,7 +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,
@@ -2314,7 +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;
 	}
 
@@ -2375,7 +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)
@@ -2413,9 +2429,9 @@ 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);
+		tree_content_get(&b->branch_tree, s, &leaf, 1);
 	if (!leaf.versions[1].mode)
 		die("Path %s not in branch", s);
 	if (!*d) {	/* C "path/to/subdir" "" */
@@ -2521,7 +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))
@@ -3051,6 +3067,8 @@ static void parse_ls(struct branch *b)
 		struct object_entry *e = parse_treeish_dataref(&p);
 		root = new_tree_entry();
 		hashcpy(root->versions[1].sha1, e->idx.sha1);
+		if (!is_null_sha1(root->versions[1].sha1))
+			root->versions[1].mode = S_IFDIR;
 		load_tree(root);
 		if (*p++ != ' ')
 			die("Missing space after tree-ish: %s", command_buf.buf);
@@ -3065,7 +3083,7 @@ static void parse_ls(struct branch *b)
 			die("Garbage after path in: %s", command_buf.buf);
 		p = uq.buf;
 	}
-	tree_content_get(root, p, &leaf);
+	tree_content_get(root, p, &leaf, 1);
 	/*
 	 * A directory in preparation would have a sha1 of zero
 	 * until it is saved.  Save, for simplicity.
diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index ac6f3b6af2..31a770d9bc 100755
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -1031,6 +1031,32 @@ test_expect_success \
 	 git diff-tree -M -r M3^ M3 >actual &&
 	 compare_diff_raw expect actual'
 
+cat >input <<INPUT_END
+commit refs/heads/M4
+committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+data <<COMMIT
+rename root
+COMMIT
+
+from refs/heads/M2^0
+R "" sub
+
+INPUT_END
+
+cat >expect <<EOF
+:100644 100644 7123f7f44e39be127c5eb701e5968176ee9d78b1 7123f7f44e39be127c5eb701e5968176ee9d78b1 R100	file2/oldf	sub/file2/oldf
+:100755 100755 85df50785d62d3b05ab03d9cbf7e4a0b49449730 85df50785d62d3b05ab03d9cbf7e4a0b49449730 R100	file4	sub/file4
+:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc R100	i/am/new/to/you	sub/i/am/new/to/you
+:100755 100755 e74b7d465e52746be2b4bae983670711e6e66657 e74b7d465e52746be2b4bae983670711e6e66657 R100	newdir/exec.sh	sub/newdir/exec.sh
+:100644 100644 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 R100	newdir/interesting	sub/newdir/interesting
+EOF
+test_expect_success \
+	'M: rename root to subdirectory' \
+	'git fast-import <input &&
+	 git diff-tree -M -r M4^ M4 >actual &&
+	 cat actual &&
+	 compare_diff_raw expect actual'
+
 ###
 ### series N
 ###
@@ -1228,6 +1254,29 @@ test_expect_success \
 	 compare_diff_raw expect actual'
 
 test_expect_success \
+	'N: copy root by path' \
+	'cat >expect <<-\EOF &&
+	:100755 100755 f1fb5da718392694d0076d677d6d0e364c79b0bc f1fb5da718392694d0076d677d6d0e364c79b0bc C100	file2/newf	oldroot/file2/newf
+	:100644 100644 7123f7f44e39be127c5eb701e5968176ee9d78b1 7123f7f44e39be127c5eb701e5968176ee9d78b1 C100	file2/oldf	oldroot/file2/oldf
+	:100755 100755 85df50785d62d3b05ab03d9cbf7e4a0b49449730 85df50785d62d3b05ab03d9cbf7e4a0b49449730 C100	file4	oldroot/file4
+	:100755 100755 e74b7d465e52746be2b4bae983670711e6e66657 e74b7d465e52746be2b4bae983670711e6e66657 C100	newdir/exec.sh	oldroot/newdir/exec.sh
+	:100644 100644 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 fcf778cda181eaa1cbc9e9ce3a2e15ee9f9fe791 C100	newdir/interesting	oldroot/newdir/interesting
+	EOF
+	 cat >input <<-INPUT_END &&
+	commit refs/heads/N-copy-root-path
+	committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+	data <<COMMIT
+	copy root directory by (empty) path
+	COMMIT
+
+	from refs/heads/branch^0
+	C "" oldroot
+	INPUT_END
+	 git fast-import <input &&
+	 git diff-tree -C --find-copies-harder -r branch N-copy-root-path >actual &&
+	 compare_diff_raw expect actual'
+
+test_expect_success \
 	'N: delete directory by copying' \
 	'cat >expect <<-\EOF &&
 	OBJID
@@ -2934,4 +2983,20 @@ test_expect_success 'S: ls with garbage after sha1 must fail' '
 	test_i18ngrep "space after tree-ish" err
 '
 
+###
+### series T (ls)
+###
+# Setup is carried over from series S.
+
+test_expect_success 'T: ls root tree' '
+	sed -e "s/Z\$//" >expect <<-EOF &&
+	040000 tree $(git rev-parse S^{tree})	Z
+	EOF
+	sha1=$(git rev-parse --verify S) &&
+	git fast-import --import-marks=marks <<-EOF >actual &&
+	ls $sha1 ""
+	EOF
+	test_cmp expect actual
+'
+
 test_done