From: Lucas Zamboni Orioli via GitGitGadget Date: Thu, 23 Jul 2026 21:40:29 GMT Subject: [PATCH v3 0/2] mv: report missing destination leading directory Message-ID: In-Reply-To: Changes in v3: * changed check from lstat to stat so it follows symlinks as suggested by Junio C Hamano * added ENOTDIR verification as suggested by Junio C Hamano * added S_ISDIR check to catch files as path components as suggested by Junio C Hamano * fixed indentation Changes in v2: * altered the error message to include both source and destination as suggested by Ben Knoble Lucas Zamboni Orioli (2): mv: name both source and destination when rename fails mv: check for missing destination directory before renaming builtin/mv.c | 26 +++++++++++++++++++++++++- t/t7001-mv.sh | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 74 insertions(+), 1 deletion(-) base-commit: 9a0c4701dcd5725c4184599322b52933ff5005ca Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2356%2FZamboniL%2Fmv-detect-non-existing-target-folder-v3 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2356/ZamboniL/mv-detect-non-existing-target-folder-v3 Pull-Request: https://github.com/git/git/pull/2356 Range-diff vs v2: 1: 0d67da588b = 1: 0d67da588b mv: name both source and destination when rename fails 2: 1a790e0016 ! 2: 5ac1587362 mv: check for missing destination directory before renaming @@ Commit message with ENOENT. The checking phase already rejects a missing destination directory when the destination ends in a slash, but a destination that names a file inside a non-existent directory is not caught and only - fails later at the syscall. As a consequence "git mv -n" does not - detect the problem either: the dry run never reaches rename(2) and - reports a move that would not actually succeed. + fails later at the syscall. The same is true when a leading path + component exists but is not a directory: rename(2) fails with ENOTDIR, + again only at the syscall. As a consequence "git mv -n" does not detect + either problem: the dry run never reaches rename(2) and reports a move + that would not actually succeed. Detect this during the checking phase. For entries that will be renamed - on disk, stat the destination's leading directory and, if it is - missing, fail with the existing "destination directory does not exist" - message. Guard the check with the same condition under which rename(2) - is invoked, so that directory moves, whose child entries are expanded - to paths under a not-yet-created directory, and sparse or out-of-cone - destinations, which are not written to the worktree, are not flagged - incorrectly. + on disk, stat the destination's leading directory and fail with a + suitable message if it is missing or is not a directory. stat() is used + rather than lstat() so that the check follows symlinks the same way + rename(2) does: a symlink to a directory is accepted, while a symlink to + a file is rejected. A missing directory or a non-directory path + component (ENOENT or ENOTDIR) reuses the existing "destination directory + does not exist" message; a leading component that resolves to a + non-directory reports "destination is not a directory". Other stat() + errors fall through to rename(2), which reports them as before. - This is a best-effort diagnostic rather than a guarantee: the - destination directory can still disappear between the check and the - rename(2). It fixes the common case and, unlike the syscall path, - lets "git mv -n" report the failure. - - Add tests covering both the error path and the dry-run detection. + Add tests covering the missing directory, a path component that is a + file, a symlink to a file, a symlink to a directory (which must still + succeed), and dry-run detection. Signed-off-by: Lucas Zamboni Orioli @@ builtin/mv.c: dir_check: } + /* -+ * If we are going to move SRC to DST on disk, DST's leading -+ * directories must already exist. -+ */ ++ * If we are going to move SRC to DST on disk, DST's leading ++ * directories must already exist. ++ */ + if (!(modes[i] & (INDEX | SPARSE | SKIP_WORKTREE_DIR)) && + !(dst_mode & (SKIP_WORKTREE_DIR | SPARSE))) { -+ char *dst_dir = xstrdup(dst); -+ char *slash = strrchr(dst_dir, '/'); ++ char *dst_dir = xstrdup(dst); ++ char *slash = strrchr(dst_dir, '/'); + -+ if (slash) { -+ struct stat dir_st; -+ *slash = '\0'; -+ if (lstat(dst_dir, &dir_st) < 0 && errno == ENOENT) { -+ free(dst_dir); -+ bad = _("destination directory does not exist"); -+ goto act_on_entry; -+ } -+ } -+ free(dst_dir); ++ if (slash) { ++ struct stat dir_st; ++ *slash = '\0'; ++ if (stat(dst_dir, &dir_st) < 0) { ++ /* other errors fall through to rename(), which reports them */ ++ if (errno == ENOENT || errno == ENOTDIR) ++ bad = _("destination directory does not exist"); ++ } else if (!S_ISDIR(dir_st.st_mode)) ++ bad = _("destination is not a directory"); ++ } ++ free(dst_dir); ++ if (bad) ++ goto act_on_entry; + } + if (ignore_sparse && @@ t/t7001-mv.sh: test_expect_success 'clean up' ' git reset --hard ' -+test_expect_success 'moving to non-existent destination parent directory' ' ++test_expect_success 'moving to a non-existent path component in the destination' ' + git reset --hard && + mkdir -p from && + echo content >from/file && @@ t/t7001-mv.sh: test_expect_success 'clean up' ' + test_grep "destination directory does not exist" actual +' + ++test_expect_success 'moving to a destination with a file as a path component' ' ++ git reset --hard && ++ mkdir -p from && ++ echo contents >from/file && ++ echo blocker >not-dir && ++ git add from/file && ++ test_must_fail git mv from/file not-dir/file 2>actual && ++ test_grep "destination is not a directory" actual ++' ++ ++test_expect_success SYMLINKS 'moving to a destination with a symlink to a file as a path component' ' ++ git reset --hard && ++ mkdir -p from && ++ echo contents >from/file && ++ echo target >regular && ++ ln -s regular link-to-file && ++ git add from/file && ++ test_must_fail git mv from/file link-to-file/file 2>actual && ++ test_grep "not a directory" actual ++' ++ ++test_expect_success SYMLINKS 'moving to a destination with a symlink to a directory' ' ++ git reset --hard && ++ mkdir -p from realdir && ++ echo contents >from/file && ++ ln -s realdir link-to-dir && ++ git add from/file && ++ git mv from/file link-to-dir/file && ++ test_path_is_file realdir/file ++' ++ +test_expect_success 'mv --dry-run detects non-existent destination parent directory' ' ++ git reset --hard && ++ mkdir -p from && ++ echo content >from/file && ++ git add from/file && + test_must_fail git mv -n from/file no-such-dir/file 2>actual && + test_grep "destination directory does not exist" actual +' -- gitgitgadget