Remove an assertion that would cause BAT to raise and exception and halt
when a library blend file is missing. This assertion was fine for aiding
the coding of the library, but now gets in the way of tracing dependencies
of partially checked-out projects.
This commit fixes a bunch of issues at the same time, as they are all
related to path handling:
- `pathlib.Path.resolve()` or `.absolute()` are replaced by
`bpathlib.make_absolute()`. The latter does NOT follow symlinks and does
NOT network mounts from a drive letter to UNC notation. This also has
advantages on non-Windows sytems, as it allows BAT-packing a directory
structure with symlinked files (such as a Shaman checkout).
- Better handling of drive letters, and of paths that cross drive
boundaries.
- Better testing of Windows-specific cases when running the tests on
Windows, and of POSIX-specific cases on other platforms.
Thanks to @wisaac for starting this patch in D6676.
Thanks to @jbakker for pointing out the drive letter issue. This fixes
T70655.
External files with the same path on different drives are packed as a
single file. In this commit the drive letter is taken into account when
determining the path inside `_outside_project`, so that they are distinct.
This is the same version as 0.99, just released as 1.0 to note the
maturity of the code (it's been used successfully for months at the Blender
Animation Studio).
