Path.is_absolute() only recognizes the current platform's own path
syntax, so a manifest key using a different platform's absolute form,
a POSIX /abs/path loaded on Windows, or a C: or UNC path loaded on
POSIX, was wrongly judged relative and joined onto the scan root,
producing a nonsense path like root plus C: colon Users colon x colon
foo dot py instead of being left alone. A manifest genuinely can move
between platforms, which is this whole module's own stated scope for
tolerating format mismatches.
A new helper checks for a leading slash or backslash or a drive
letter pattern in addition to the native is_absolute check, so a
foreign absolute key is recognized and passed through unchanged on
any platform instead of only the one that produced it.
Fixes review finding on PR 3781.
(cherry picked from commit 7f47a5fef4)
ayushcodes10
007844e0c8