1 files changed, 29 insertions, 1 deletions

diff --git a/vendor/golang.org/x/sys/windows/syscall_windows.go b/vendor/golang.org/x/sys/windows/syscall_windows.go
index b3e5503..12c0544 100644
--- a/vendor/golang.org/x/sys/windows/syscall_windows.go
+++ b/vendor/golang.org/x/sys/windows/syscall_windows.go
@@ -13,6 +13,8 @@ import (
         "time"
         "unicode/utf16"
         "unsafe"
+
+        "golang.org/x/sys/internal/unsafeheader"
 )
 
 type Handle uintptr
@@ -117,6 +119,32 @@ func UTF16PtrFromString(s string) (*uint16, error) {
         return &a[0], nil
 }
 
+// UTF16PtrToString takes a pointer to a UTF-16 sequence and returns the corresponding UTF-8 encoded string.
+// If the pointer is nil, this returns the empty string. This assumes that the UTF-16 sequence is terminated
+// at a zero word; if the zero word is not present, the program may crash.
+func UTF16PtrToString(p *uint16) string {
+        if p == nil {
+                return ""
+        }
+        if *p == 0 {
+                return ""
+        }
+
+        // Find NUL terminator.
+        n := 0
+        for ptr := unsafe.Pointer(p); *(*uint16)(ptr) != 0; n++ {
+                ptr = unsafe.Pointer(uintptr(ptr) + unsafe.Sizeof(*p))
+        }
+
+        var s []uint16
+        h := (*unsafeheader.Slice)(unsafe.Pointer(&s))
+        h.Data = unsafe.Pointer(p)
+        h.Len = n
+        h.Cap = n
+
+        return string(utf16.Decode(s))
+}
+
 func Getpagesize() int { return 4096 }
 
 // NewCallback converts a Go function to a function pointer conforming to the stdcall calling convention.
@@ -1383,7 +1411,7 @@ func (t Token) KnownFolderPath(folderID *KNOWNFOLDERID, flags uint32) (string, e
                 return "", err
         }
         defer CoTaskMemFree(unsafe.Pointer(p))
-        return UTF16ToString((*[(1 << 30) - 1]uint16)(unsafe.Pointer(p))[:]), nil
+        return UTF16PtrToString(p), nil
 }
 
 // RtlGetVersion returns the version of the underlying operating system, ignoring