* small optimisation for ToSingleByteFileSystemEncodedFileName(rawbytestring):

    don't call SetCodePage() if the input already has the correct code page
    (SetCodePage would always make the string unique, which is not necessary)

git-svn-id: branches/cpstrrtl@24962 -

rtl/inc/ustrings.inc

@@ -2296,5 +2296,6 @@ End;
 Function ToSingleByteFileSystemEncodedFileName(const Str: RawByteString): RawByteString;
 Begin
   Result:=Str;
-  SetCodePage(Result,DefaultFileSystemCodePage,True);
+  if StringCodePage(Result)<>DefaultFileSystemCodePage then
+    SetCodePage(Result,DefaultFileSystemCodePage,True);
 End;