Hidden files and folders are not mirrored correctly when source is a relative path

[mzoellner]

Describe the bug
When the source of a zstd command is given as a relative path, hidden files and folders are not correctly copied to the target folder, but into the parent of the target folder.

To Reproduce
I created a small repository that makes it easier to reproduce the issue: https://github.com/mzoellner/zstd-repro

Imagine a folder structure like this:

/opt/source/file
/opt/source/.hidden-file
/opt/source/.hidden-folder/file-in-hidden-folder

Then run the following command
mkdir -p /opt/target && cd /opt/source && zstd -r --output-dir-mirror /opt/target ./

.hidden-file.zst and file-in-hidden-folder.zst will both end up in /opt instead of /opt/target

Expected behavior
Hidden files and folders from source are mirrored in target

Desktop (please complete the following information):

• OS: Debian 12 / Ubuntu 22.04
• Version zstd 1.5.5

[felixhandte]

Hi @mzoellner,

Thanks for the report!

I have reproduced the issue. This is the offending check:

zstd/programs/util.c

Lines 1122 to 1123 in 63779c7

	if (dir2[0] == '.')
	return outDirBuffer;

Now I just need to figure out why this check exists before I remove it...

But I'll get a fix up shortly.

[mzoellner]

Thank you for fixing this @felixhandte
Much appreciated.