builtin git-mv: support moving directories

This fixes the builtin mv for the test which Josef provided, and also
fixes moving directories into existing directories, as noted by Jon Smirl.
In case the destination exists, fail early (this cannot be overridden
by -f).

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

builtin-mv.c

@@ -42,6 +42,18 @@ static void show_list(const char *label, struct path_list *list)
 	}
 }
 
+static const char *add_slash(const char *path)
+{
+	int len = strlen(path);
+	if (path[len - 1] != '/') {
+		char *with_slash = xmalloc(len + 2);
+		memcpy(with_slash, path, len);
+		strcat(with_slash + len, "/");
+		return with_slash;
+	}
+	return path;
+}
+
 static struct lock_file lock_file;
 
 int cmd_mv(int argc, const char **argv, char **envp)
@@ -50,6 +62,7 @@ int cmd_mv(int argc, const char **argv, char **envp)
 	int verbose = 0, show_only = 0, force = 0, ignore_errors = 0;
 	const char *prefix = setup_git_directory();
 	const char **source, **destination, **dest_path;
+	enum update_mode { BOTH = 0, WORKING_DIRECTORY, INDEX } *modes;
 	struct stat st;
 	struct path_list overwritten = {NULL, 0, 0, 0};
 	struct path_list src_for_dst = {NULL, 0, 0, 0};
@@ -94,11 +107,14 @@ int cmd_mv(int argc, const char **argv, char **envp)
 		usage(builtin_mv_usage);
 
 	source = copy_pathspec(prefix, argv + i, count, 0);
+	modes = xcalloc(count, sizeof(enum update_mode));
 	dest_path = copy_pathspec(prefix, argv + argc - 1, 1, 0);
 
-	if (!lstat(dest_path[0], &st) && S_ISDIR(st.st_mode))
+	if (!lstat(dest_path[0], &st) &&
+			S_ISDIR(st.st_mode)) {
+		dest_path[0] = add_slash(dest_path[0]);
 		destination = copy_pathspec(dest_path[0], argv + i, count, 1);
-	else {
+	} else {
 		if (count != 1)
 			usage(builtin_mv_usage);
 		destination = dest_path;
@@ -114,7 +130,64 @@ int cmd_mv(int argc, const char **argv, char **envp)
 
 		if (lstat(source[i], &st) < 0)
 			bad = "bad source";
-		else if (lstat(destination[i], &st) == 0) {
+
+		if (S_ISDIR(st.st_mode)) {
+			const char *dir = source[i], *dest_dir = destination[i];
+			int first, last, len = strlen(dir);
+
+			if (lstat(dest_dir, &st) == 0) {
+				bad = "cannot move directory over file";
+				goto next;
+			}
+
+			modes[i] = WORKING_DIRECTORY;
+
+			first = cache_name_pos(source[i], len);
+			if (first >= 0)
+				die ("Huh? %s/ is in index?", dir);
+
+			first = -1 - first;
+			for (last = first; last < active_nr; last++) {
+				const char *path = active_cache[last]->name;
+				if (strncmp(path, dir, len) || path[len] != '/')
+					break;
+			}
+
+			if (last - first < 1)
+				bad = "source directory is empty";
+			else if (!bad) {
+				int j, dst_len = strlen(dest_dir);
+
+				if (last - first > 0) {
+					source = realloc(source,
+							(count + last - first)
+							* sizeof(char *));
+					destination = realloc(destination,
+							(count + last - first)
+							* sizeof(char *));
+					modes = realloc(modes,
+							(count + last - first)
+							* sizeof(enum update_mode));
+				}
+
+				dest_dir = add_slash(dest_dir);
+
+				for (j = 0; j < last - first; j++) {
+					const char *path =
+						active_cache[first + j]->name;
+					source[count + j] = path;
+					destination[count + j] =
+						prefix_path(dest_dir, dst_len,
+							path + len);
+					modes[count + j] = INDEX;
+				}
+				count += last - first;
+			}
+
+			goto next;
+		}
+
+		if (!bad && lstat(destination[i], &st) == 0) {
 			bad = "destination exists";
 			if (force) {
 				/*
@@ -147,6 +220,7 @@ int cmd_mv(int argc, const char **argv, char **envp)
 				path_list_insert(destination[i], &src_for_dst);
 		}
 
+next:
 		if (bad) {
 			if (ignore_errors) {
 				if (--count > 0) {
@@ -157,7 +231,7 @@ int cmd_mv(int argc, const char **argv, char **envp)
 						(count - i) * sizeof(char *));
 				}
 			} else
-				die ("Error: %s, source=%s, destination=%s",
+				die ("%s, source=%s, destination=%s",
 				     bad, source[i], destination[i]);
 		}
 	}
@@ -166,12 +240,15 @@ int cmd_mv(int argc, const char **argv, char **envp)
 		if (show_only || verbose)
 			printf("Renaming %s to %s\n",
 			       source[i], destination[i]);
-		if (!show_only &&
+		if (!show_only && modes[i] != INDEX &&
 		    rename(source[i], destination[i]) < 0 &&
 		    !ignore_errors)
 			die ("renaming %s failed: %s",
 			     source[i], strerror(errno));
 
+		if (modes[i] == WORKING_DIRECTORY)
+			continue;
+
 		if (cache_name_pos(source[i], strlen(source[i])) >= 0) {
 			path_list_insert(source[i], &deleted);
 

t/t7001-mv.sh

@@ -74,4 +74,8 @@ test_expect_success \
      git-diff-tree -r -M --name-status  HEAD^ HEAD | \
      grep -E "^R100.+path2/README.+path1/path2/README"'
 
+test_expect_failure \
+    'do not move directory over existing directory' \
+    'mkdir path0 && mkdir path0/path2 && git-mv path2 path0'
+
 test_done