NODEFS cannot read files from sparse disk image when mounted with absolute path under OSX

[janjongboom]

I have a sparse disk image (f.e. to have a case-sensitive file system) on OS/X, which is mapped from /Volumes/repos to /Users/janjongboom/repos. Now when I mount my full file system through NODEFS:

FS.mount(NODEFS, { root: '/' }, '/test');

And then trying to read a file from the disk image through C++:

FILE* fd = fopen("/test/Users/janjongboom/repos/janos/README.md", "r");

It fails, because NODEFS readlink() returns /Volumes/repos. Which is incorrect. It should take the mountpoint of the filesystem into account, because this folder is mapped on /test/Volumes/repos.

Patch in #3223

[stale]

This issue has been automatically marked as stale because there has been no activity in the past 2 years. It will be closed automatically if no further activity occurs in the next 7 days. Feel free to re-open at any time if this issue is still relevant.

[sbc100]

I now think the fix for this issue was wrong. If you have links to /Volumes/repos in your filesystem, but /Volumes/repos is not part of the emscripten VFS then they should not be readable. i.e. they are effectivly dangling symlinks from the POV of the emscripten filesystem, even though they point a valid location in the external filesystem.

For this kind of thing to would you would either need to mount /Volumes/repos inside the VFS, or use NODERAWFS.

[sbc100]

We are looking at effectively reverting this change in #21805