Change #252865

Comments

curlx: add `curlx_rename()`, fix to support long filenames on Windows

Move existing `Curl_rename()` `rename()` wrapper from lib to
curlx/fopen, and make it a curlx macro/function. To allow using
the local worker function to fixup long filenames on Windows.

Then fix the Windows-specific rename implementation to support long
filenames. This operation may happen when using a cookie jar, HSTS cache
or alt-svc cache, via libcurl or the curl tool.

Before this patch, when passing a long filename to the above options,
a `<random>.tmp` file was left on the disk without renaming it to the
filename passed to curl. There was also 1 second delay for each
attempted rename operation.

Also:
- checksrc: ban raw `rename()` and `MoveFileEx*()` functions.
- Note: `Curl_rename()` returned 1 on failure before this patch, while
  `curlx_rename()` returns -1 after, to match POSIX `rename()`.

Refs:
https://learn.microsoft.com/windows/win32/api/winbase/nf-winbase-movefileexa
https://learn.microsoft.com/windows/win32/fileio/maximum-file-path-limitation

Ref: #20040

Closes #20042

Changed files

• docs/internals/CODE_STYLE.md
• lib/Makefile.inc
• lib/altsvc.c
• lib/cookie.c
• lib/curlx/fopen.c
• lib/curlx/fopen.h
• lib/hsts.c
• lib/rename.c
• lib/rename.h
• scripts/checksrc.pl