--- orig/path_lite_windowsspecific.go 2026-03-28 16:15:19 +++ path_lite_windowsspecific.go 2026-03-28 16:14:52 @@ -2,15 +2,8 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. -package filepathlite +package winpath -import ( - "internal/bytealg" - "internal/stringslite" - "internal/syscall/windows" - "syscall" -) - const ( Separator = '\\' // OS-specific path separator ListSeparator = ';' // OS-specific path list separator @@ -20,159 +13,6 @@ return c == '\\' || c == '/' } -func isLocal(path string) bool { - if path == "" { - return false - } - if IsPathSeparator(path[0]) { - // Path rooted in the current drive. - return false - } - if stringslite.IndexByte(path, ':') >= 0 { - // Colons are only valid when marking a drive letter ("C:foo"). - // Rejecting any path with a colon is conservative but safe. - return false - } - hasDots := false // contains . or .. path elements - for p := path; p != ""; { - var part string - part, p, _ = cutPath(p) - if part == "." || part == ".." { - hasDots = true - } - if isReservedName(part) { - return false - } - } - if hasDots { - path = Clean(path) - } - if path == ".." || stringslite.HasPrefix(path, `..\`) { - return false - } - return true -} - -func localize(path string) (string, error) { - for i := 0; i < len(path); i++ { - switch path[i] { - case ':', '\\', 0: - return "", errInvalidPath - } - } - containsSlash := false - for p := path; p != ""; { - // Find the next path element. - var element string - i := bytealg.IndexByteString(p, '/') - if i < 0 { - element = p - p = "" - } else { - containsSlash = true - element = p[:i] - p = p[i+1:] - } - if isReservedName(element) { - return "", errInvalidPath - } - } - if containsSlash { - // We can't depend on strings, so substitute \ for / manually. - buf := []byte(path) - for i, b := range buf { - if b == '/' { - buf[i] = '\\' - } - } - path = string(buf) - } - return path, nil -} - -// isReservedName reports if name is a Windows reserved device name. -// It does not detect names with an extension, which are also reserved on some Windows versions. -// -// For details, search for PRN in -// https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file. -func isReservedName(name string) bool { - // Device names can have arbitrary trailing characters following a dot or colon. - base := name - for i := 0; i < len(base); i++ { - switch base[i] { - case ':', '.': - base = base[:i] - } - } - // Trailing spaces in the last path element are ignored. - for len(base) > 0 && base[len(base)-1] == ' ' { - base = base[:len(base)-1] - } - if !isReservedBaseName(base) { - return false - } - if len(base) == len(name) { - return true - } - // The path element is a reserved name with an extension. - // Since Windows 11, reserved names with extensions are no - // longer reserved. For example, "CON.txt" is a valid file - // name. Use RtlIsDosDeviceName_U to see if the name is reserved. - p, err := syscall.UTF16PtrFromString(name) - if err != nil { - return false - } - return windows.RtlIsDosDeviceName_U(p) > 0 -} - -func isReservedBaseName(name string) bool { - if len(name) == 3 { - switch string([]byte{toUpper(name[0]), toUpper(name[1]), toUpper(name[2])}) { - case "CON", "PRN", "AUX", "NUL": - return true - } - } - if len(name) >= 4 { - switch string([]byte{toUpper(name[0]), toUpper(name[1]), toUpper(name[2])}) { - case "COM", "LPT": - if len(name) == 4 && '1' <= name[3] && name[3] <= '9' { - return true - } - // Superscript ¹, ², and ³ are considered numbers as well. - switch name[3:] { - case "\u00b2", "\u00b3", "\u00b9": - return true - } - return false - } - } - - // Passing CONIN$ or CONOUT$ to CreateFile opens a console handle. - // https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea#consoles - // - // While CONIN$ and CONOUT$ aren't documented as being files, - // they behave the same as CON. For example, ./CONIN$ also opens the console input. - if len(name) == 6 && name[5] == '$' && equalFold(name, "CONIN$") { - return true - } - if len(name) == 7 && name[6] == '$' && equalFold(name, "CONOUT$") { - return true - } - return false -} - -func equalFold(a, b string) bool { - if len(a) != len(b) { - return false - } - for i := 0; i < len(a); i++ { - if toUpper(a[i]) != toUpper(b[i]) { - return false - } - } - return true -} - func toUpper(c byte) byte { if 'a' <= c && c <= 'z' { return c - ('a' - 'A') @@ -180,13 +20,11 @@ return c } -// IsAbs reports whether the path is absolute. func IsAbs(path string) (b bool) { l := volumeNameLen(path) if l == 0 { return false } - // If the volume name starts with a double slash, this is an absolute path. if IsPathSeparator(path[0]) && IsPathSeparator(path[1]) { return true } @@ -197,46 +35,21 @@ return IsPathSeparator(path[0]) } -// volumeNameLen returns length of the leading volume name on Windows. -// It returns 0 elsewhere. -// -// See: -// https://learn.microsoft.com/en-us/dotnet/standard/io/file-path-formats -// https://googleprojectzero.blogspot.com/2016/02/the-definitive-guide-on-win32-to-nt.html func volumeNameLen(path string) int { switch { case len(path) >= 2 && path[1] == ':': - // Path starts with a drive letter. - // - // Not all Windows functions necessarily enforce the requirement that - // drive letters be in the set A-Z, and we don't try to here. - // - // We don't handle the case of a path starting with a non-ASCII character, - // in which case the "drive letter" might be multiple bytes long. return 2 case len(path) == 0 || !IsPathSeparator(path[0]): - // Path does not have a volume component. return 0 case pathHasPrefixFold(path, `\\.\UNC`): - // We're going to treat the UNC host and share as part of the volume - // prefix for historical reasons, but this isn't really principled; - // Windows's own GetFullPathName will happily remove the first - // component of the path in this space, converting - // \\.\unc\a\b\..\c into \\.\unc\a\c. return uncLen(path, len(`\\.\UNC\`)) case pathHasPrefixFold(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 treat the next component after the \\.\ prefix as - // part of the volume name, which means Clean(`\\?\c:\`) - // won't remove the trailing \. (See #64028.) if len(path) == 3 { - return 3 // exactly \\. + return 3 } _, rest, ok := cutPath(path[4:]) if !ok { @@ -245,15 +58,11 @@ return len(path) - len(rest) - 1 case len(path) >= 2 && IsPathSeparator(path[1]): - // Path starts with \\, and is a UNC path. return uncLen(path, 2) } return 0 } -// pathHasPrefixFold tests whether the path s begins with prefix, -// ignoring case and treating all path separators as equivalent. -// If s is longer than prefix, then s[len(prefix)] must be a path separator. func pathHasPrefixFold(s, prefix string) bool { if len(s) < len(prefix) { return false @@ -273,9 +82,6 @@ return true } -// uncLen returns the length of the volume prefix of a UNC path. -// prefixLen is the prefix prior to the start of the UNC host; -// for example, for "//host/share", the prefixLen is len("//")==2. func uncLen(path string, prefixLen int) int { count := 0 for i := prefixLen; i < len(path); i++ { @@ -289,7 +95,6 @@ return len(path) } -// cutPath slices path around the first path separator. func cutPath(path string) (before, after string, found bool) { for i := range path { if IsPathSeparator(path[i]) { @@ -299,15 +104,10 @@ return path, "", false } -// postClean adjusts the results of Clean to avoid turning a relative path -// into an absolute or rooted one. func postClean(out *lazybuf) { if out.volLen != 0 || out.buf == nil { return } - // If a ':' appears in the path element at the start of a path, - // insert a .\ at the beginning to avoid converting relative paths - // like a/../c: into c:. for _, c := range out.buf { if IsPathSeparator(c) { break @@ -317,9 +117,6 @@ return } } - // If a path begins with \??\, insert a \. at the beginning - // to avoid converting paths like \a\..\??\c:\x into \??\c:\x - // (equivalent to c:\x). if len(out.buf) >= 3 && IsPathSeparator(out.buf[0]) && out.buf[1] == '?' && out.buf[2] == '?' { out.prepend(Separator, '.') }