(This CL takes the tests and some ideas from the abandoned CL 263538).
fixLongPath is used on Windows to process all path names
before syscalls to switch them to extended-length format
(with prefix \\?\) to workaround a historical limit
of 260-ish characters.
This CL updates fixLongPath to convert relative paths to absolute
paths if the working directory plus the relative path exceeds
MAX_PATH. This is necessary because the Windows API does not
support extended-length paths for relative paths.
This CL also adds support for fixing device paths (\\.\-prefixed),
which were not previously normalized.
Fixes #41734
Fixes #21782
Fixes #36375
Cq-Include-Trybots: luci.golang.try:gotip-windows-amd64-longtest,gotip-windows-amd64-race,gotip-windows-arm64 Co-authored-by: Giovanni Bajo <rasky@develer.com>
Change-Id: I63cfb79f3ae6b9d42e07deac435b730d97a6f492
Reviewed-on: https://go-review.googlesource.com/c/go/+/574695
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Damien Neil <dneil@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>