Thank you very much. I'll give this a try. Did your problem only occur
in D7 using pre-XP versions of Windows?

--- In IBObjects@yahoogroups.com, "Florian Hector" <FHector@w...> wrote:
>
> John,
>
> I had a similar problem a while back and came across this fix.
> Just add the following unit to your project.
>
> unit D7ComboBoxStringsGetPatch;
>
> // The patch fixes TCustomComboBoxStrings.Get method for empty
string item
> in Delphi 7.
>
> interface
>
> {$IF RTLVersion <> 15.0}
> 'This patch is intended for Delphi 7 only';
> {$IFEND}
>
> implementation
>
> uses
> Windows, SysUtils, StdCtrls;
>
> resourcestring
> RsPatchingFailed = 'TCustomComboBoxStrings.Get patching failed.';
>
> type
> TPatchResult = (prNotNeeded, prOk, prError);
>
> function PatchCode(RoutineStartAddr: Pointer; PatchOffset: Cardinal;
> OriginalCode: Pointer;
> OriginalCodeLen: Cardinal; PatchedCode: Pointer; PatchedCodeLen:
> Cardinal): TPatchResult;
> const
> JmpOpCode = $25FF;
> type
> PPackageThunk = ^TPackageThunk;
> TPackageThunk = packed record
> JmpInstruction: Word;
> JmpAddress: PPointer;
> end;
> var
> CodeStart: Pointer;
> BytesWritten: DWORD;
> begin
> if FindClassHInstance(System.TObject) <> HInstance then
> with PPackageThunk(RoutineStartAddr)^ do
> if JmpInstruction = JmpOpCode then
> RoutineStartAddr := JmpAddress^
> else
> begin
> Result := prError;
> Exit;
> end;
> CodeStart := Pointer(LongWord(RoutineStartAddr) + PatchOffset);
> if CompareMem(CodeStart, OriginalCode, OriginalCodeLen) then
> begin
> if WriteProcessMemory(GetCurrentProcess, CodeStart, PatchedCode,
> PatchedCodeLen, BytesWritten) and
> (BytesWritten = PatchedCodeLen) then
> begin
> FlushInstructionCache(GetCurrentProcess, CodeStart,
PatchedCodeLen);
> Result := prOk;
> end
> else
> Result := prError;
> end
> else
> Result := prNotNeeded;
> end;
>
> type
> TCustomComboBoxStringsHack = class(TCustomComboBoxStrings);
>
> function AddrOfTCustomComboBoxStringsGet: Pointer;
> begin
> Result := @...;
> end;
>
> procedure PatchTCustomComboBoxStringsGet;
> const
> OriginalCode: Cardinal = $74FFF883; // CMP EAX, -1 | JZ +$26
> PatchedCode: Cardinal = $7E00F883; // CMP EAX, 0 | JLE +$26
> PatchOffset = $1F;
> var
> PatchResult: TPatchResult;
> begin
> PatchResult := PatchCode(AddrOfTCustomComboBoxStringsGet, PatchOffset,
> @OriginalCode, SizeOf(OriginalCode),
> @PatchedCode, SizeOf(PatchedCode));
> case PatchResult of
> prError:
> begin
> if IsConsole then
> WriteLn(ErrOutput, RsPatchingFailed)
> else
> MessageBox(0, PChar(RsPatchingFailed), nil, MB_OK or
MB_ICONSTOP
> or MB_TASKMODAL);
> RunError(1);
> end;
> end;
> end;
>
> initialization
> PatchTCustomComboBoxStringsGet;
>
> end.