[release-branch.go1.20] path/filepath: consider \\?\c: as a volume on Windows

While fixing several bugs in path handling on Windows,
beginning with \\?\.

Prior to #540277, VolumeName considered the first path component
after the \\?\ prefix to be part of the volume name.
After, it considered only the \\? prefix to be the volume name.

Restore the previous behavior.

For #64028.
Fixes #64040.

Change-Id: I6523789e61776342800bd607fb3f29d496257e68
Reviewed-on: https://go-review.googlesource.com/c/go/+/541175
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
(cherry picked from commit eda42f7c60adab26ed1a340414c726c4bf46b1f7)
Reviewed-on: https://go-review.googlesource.com/c/go/+/541520
Auto-Submit: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
This commit is contained in:
Damien Neil 2023-11-09 09:53:44 -08:00 committed by Gopher Robot
parent 46bc33819a
commit 1b59b017db
2 changed files with 17 additions and 18 deletions

View File

@ -108,6 +108,8 @@ var wincleantests = []PathTest{
{`//abc`, `\\abc`}, {`//abc`, `\\abc`},
{`///abc`, `\\\abc`}, {`///abc`, `\\\abc`},
{`//abc//`, `\\abc\\`}, {`//abc//`, `\\abc\\`},
{`\\?\C:\`, `\\?\C:\`},
{`\\?\C:\a`, `\\?\C:\a`},
// Don't allow cleaning to move an element with a colon to the start of the path. // Don't allow cleaning to move an element with a colon to the start of the path.
{`a/../c:`, `.\c:`}, {`a/../c:`, `.\c:`},
@ -1472,10 +1474,13 @@ var volumenametests = []VolumeNameTest{
{`//.`, `\\.`}, {`//.`, `\\.`},
{`//./`, `\\.\`}, {`//./`, `\\.\`},
{`//./NUL`, `\\.\NUL`}, {`//./NUL`, `\\.\NUL`},
{`//?/`, `\\?`}, {`//?`, `\\?`},
{`//?/`, `\\?\`},
{`//?/NUL`, `\\?\NUL`},
{`/??`, `\??`},
{`/??/`, `\??\`},
{`/??/NUL`, `\??\NUL`},
{`//./a/b`, `\\.\a`}, {`//./a/b`, `\\.\a`},
{`//?/`, `\\?`},
{`//?/`, `\\?`},
{`//./C:`, `\\.\C:`}, {`//./C:`, `\\.\C:`},
{`//./C:/`, `\\.\C:`}, {`//./C:/`, `\\.\C:`},
{`//./C:/a/b/c`, `\\.\C:`}, {`//./C:/a/b/c`, `\\.\C:`},
@ -1484,8 +1489,8 @@ var volumenametests = []VolumeNameTest{
{`//./UNC/host\`, `\\.\UNC\host\`}, {`//./UNC/host\`, `\\.\UNC\host\`},
{`//./UNC`, `\\.\UNC`}, {`//./UNC`, `\\.\UNC`},
{`//./UNC/`, `\\.\UNC\`}, {`//./UNC/`, `\\.\UNC\`},
{`\\?\x`, `\\?`}, {`\\?\x`, `\\?\x`},
{`\??\x`, `\??`}, {`\??\x`, `\??\x`},
} }
func TestVolumeName(t *testing.T) { func TestVolumeName(t *testing.T) {

View File

@ -102,12 +102,14 @@ func volumeNameLen(path string) int {
// \\.\unc\a\b\..\c into \\.\unc\a\c. // \\.\unc\a\b\..\c into \\.\unc\a\c.
return uncLen(path, len(`\\.\UNC\`)) return uncLen(path, len(`\\.\UNC\`))
case pathHasPrefixFold(path, `\\.`): case pathHasPrefixFold(path, `\\.`) ||
// Path starts with \\., and is a Local Device path. pathHasPrefixFold(path, `\\?`) || pathHasPrefixFold(path, `\??`):
// Path starts with \\.\, and is a Local Device path; or
// path starts with \\?\ or \??\ and is a Root Local Device path.
// //
// We currently treat the next component after the \\.\ prefix // We treat the next component after the \\.\ prefix as
// as part of the volume name, although there doesn't seem to be // part of the volume name, which means Clean(`\\?\c:\`)
// a principled reason to do this. // won't remove the trailing \. (See #64028.)
if len(path) == 3 { if len(path) == 3 {
return 3 // exactly \\. return 3 // exactly \\.
} }
@ -117,14 +119,6 @@ func volumeNameLen(path string) int {
} }
return len(path) - len(rest) - 1 return len(path) - len(rest) - 1
case pathHasPrefixFold(path, `\\?`) || pathHasPrefixFold(path, `\??`):
// Path starts with \\?\ or \??\, and is a Root Local Device path.
//
// While Windows usually treats / and \ as equivalent,
// /??/ does not seem to be recognized as a Root Local Device path.
// We treat it as one anyway here to be safe.
return 3
case len(path) >= 2 && isSlash(path[1]): case len(path) >= 2 && isSlash(path[1]):
// Path starts with \\, and is a UNC path. // Path starts with \\, and is a UNC path.
return uncLen(path, 2) return uncLen(path, 2)