git_futils_mkdir_*: make a relative-to-base mkdir

Untangle git_futils_mkdir from git_futils_mkdir_ext - the latter
assumes that we own everything beneath the base, as if it were
being called with a base of the repository or working directory,
and is tailored towards checkout and ensuring that there is no
bogosity beneath the base that must be cleaned up.

This is (at best) slow and (at worst) unsafe in the larger context
of a filesystem where we do not own things and cannot do things like
unlink symlinks that are in our way.

1 files changed, 14 insertions, 11 deletions

diff --git a/src/fileops.c b/src/fileops.c
index b7b55159f..b986a6546 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -18,7 +18,7 @@ GIT__USE_STRMAP
 int git_futils_mkpath2file(const char *file_path, const mode_t mode)
 {
 	return git_futils_mkdir(
-		file_path, NULL, mode,
+		file_path, mode,
 		GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST | GIT_MKDIR_VERIFY_DIR);
 }
 
@@ -331,8 +331,8 @@ GIT_INLINE(int) validate_existing(
 	return 0;
 }
 
-int git_futils_mkdir_ext(
-	const char *path,
+int git_futils_mkdir_relative(
+	const char *relative_path,
 	const char *base,
 	mode_t mode,
 	uint32_t flags,
@@ -343,9 +343,13 @@ int git_futils_mkdir_ext(
 	ssize_t root = 0, min_root_len, root_len;
 	char lastch = '/', *tail;
 	struct stat st;
+	struct git_futils_mkdir_options empty_opts = {0};
+
+	if (!opts)
+		opts = &empty_opts;
 
 	/* build path and find "root" where we should start calling mkdir */
-	if (git_path_join_unrooted(&make_path, path, base, &root) < 0)
+	if (git_path_join_unrooted(&make_path, relative_path, base, &root) < 0)
 		return -1;
 
 	if (make_path.size == 0) {
@@ -503,17 +507,16 @@ done:
 
 int git_futils_mkdir(
 	const char *path,
-	const char *base,
 	mode_t mode,
 	uint32_t flags)
 {
 	struct git_futils_mkdir_options options = {0};
-	return git_futils_mkdir_ext(path, base, mode, flags, &options);
+	return git_futils_mkdir_relative(path, NULL, mode, flags, &options);
 }
 
-int git_futils_mkdir_r(const char *path, const char *base, const mode_t mode)
+int git_futils_mkdir_r(const char *path, const mode_t mode)
 {
-	return git_futils_mkdir(path, base, mode, GIT_MKDIR_PATH);
+	return git_futils_mkdir(path, mode, GIT_MKDIR_PATH);
 }
 
 typedef struct {
@@ -777,7 +780,7 @@ static int _cp_r_mkdir(cp_r_info *info, git_buf *from)
 	/* create root directory the first time we need to create a directory */
 	if ((info->flags & GIT_CPDIR__MKDIR_DONE_FOR_TO_ROOT) == 0) {
 		error = git_futils_mkdir(
-			info->to_root, NULL, info->dirmode,
+			info->to_root, info->dirmode,
 			(info->flags & GIT_CPDIR_CHMOD_DIRS) ? GIT_MKDIR_CHMOD : 0);
 
 		info->flags |= GIT_CPDIR__MKDIR_DONE_FOR_TO_ROOT;
@@ -785,9 +788,9 @@ static int _cp_r_mkdir(cp_r_info *info, git_buf *from)
 
 	/* create directory with root as base to prevent excess chmods */
 	if (!error)
-		error = git_futils_mkdir(
+		error = git_futils_mkdir_relative(
 			from->ptr + info->from_prefix, info->to_root,
-			info->dirmode, info->mkdir_flags);
+			info->dirmode, info->mkdir_flags, NULL);
 
 	return error;
 }