Bug in StringReplace (Handling Null characters) (fixed)

Problem/Question/Abstract:

I've noticed a problem when you try to use StringReplace on a string which contains NULL (#0) characters (not null terminated).

Answer:

There is an undocumented bug in the StringReplace function.

It appears that it does not handle strings will NULL (#0) characters in them.

Here is a better routine which handles NULL correctly.


function customStringReplace(OriginalString, Pattern, Replace: string): string;

{-----------------------------------------------------------------------------

��Procedure: customStringReplace
��Date:������07-Feb-2002
��Arguments: OriginalString, Pattern, Replace: string
��Result:����string
��Description:
����Replaces Pattern with Replace in string OriginalString.
����Taking into account NULL (#0) characters.
����I cheated. This is ripped almost directly from Borland's
����StringReplace Function. The bug creeps in with the ANSIPos
����function. (Which does not detect #0 characters)

-----------------------------------------------------------------------------}

var
  ��SearchStr, Patt, NewStr: string;
  ��Offset: Integer;
begin
  ��Result := '';
  ��SearchStr := OriginalString;
  ��Patt := Pattern;
  ��NewStr := OriginalString;
  ��while SearchStr <> '' do
  ��begin
  ����Offset := Pos(Patt, SearchStr); // Was AnsiPos
  ����if Offset = 0 then
  ����begin
  ������Result := Result + NewStr;
  ������Break;
  ����end;
  ����Result := Result + Copy(NewStr, 1, Offset - 1) + Replace;
  ����NewStr := Copy(NewStr, Offset + Length(Pattern), MaxInt);
  ����SearchStr := Copy(SearchStr, Offset + Length(Patt), MaxInt);
  ��end;
end;