Two ramdisk fixes exposed by shipping the C++ header tree:
Paths longer than 100 characters (libstdc++'s pb_ds detail headers)
are split by USTAR across the name field and the 155-byte prefix
field at offset 345. The parser only read the name field, so the
tails of 7 deep header paths appeared as bogus root-level entries
while the real paths were missing. The parser now joins
prefix + '/' + name, and MaxNameLen grows to 260 to hold the full
combined path.
SYS_CHDIR validated non-root targets by opening them as files, which
only ever worked because directories used to be openable. It now uses
the ReadDir probe, which fails for nonexistent paths and regular
files on all backends (ext2/fat32 already validate the inode type).
Co-Authored-By: Claude Fable 5 <[email protected]>