Re: [ros-dev] [ros-diffs] [hbelusca] 71692: [SUBST]: CORE-10681 #comment Apply part of Peter Hater's patch proposed in CORE-10681, that is, fixing the usage of QueryDosDevice API, but without the new IsDriveUsed functionali...

[Thomas Faber]

On 2016-06-28 21:21, [e-mail] wrote:
> --- trunk/reactos/base/system/subst/subst.c	[iso-8859-1] (original)
> +++ trunk/reactos/base/system/subst/subst.c	[iso-8859-1] Tue Jun 28 19:21:08 2016
> @@ -75,81 +75,71 @@
>      if (_tcslen(Drive) > 2)
>          return FALSE;
> dwSize = sizeof(TCHAR) * MAX_PATH;
> lpTargetPath = (LPTSTR) malloc(sizeof(TCHAR) * MAX_PATH);
> if ( lpTargetPath)
> {
> dwSize = MAX_PATH;
> lpTargetPath = (LPTSTR)malloc(sizeof(TCHAR) * dwSize);
> if (!lpTargetPath)
>    return FALSE;
> CharCount = QueryDosDevice(Drive,
>                           lpTargetPath,
>                           dwSize);
> while (!CharCount &&
>       GetLastError() == ERROR_INSUFFICIENT_BUFFER)
> {
>    lpTargetPath = (LPTSTR)realloc(lpTargetPath, sizeof(TCHAR) * dwSize);

This is not how you use realloc, this causes a memory leak in case of
failure.
Also, why is there a cast here (also, for malloc above)?

Thanks.
-Thomas
>    if (lpTargetPath)
>    {
>        CharCount = QueryDosDevice(Drive,
>                                   lpTargetPath,
>                                   dwSize);
>    }
> }
> if (CharCount)
> {
>    Result = _tcsncmp(lpTargetPath, _T("\\??\\"), 4) == 0 &&
>        ( (lpTargetPath[4] >= _T('A') &&
>        lpTargetPath[4] <= _T('Z')) ||
>         (lpTargetPath[4] >= _T('a') &&
>        lpTargetPath[4] <= _T('z')) );
> }
> free(lpTargetPath);
> return Result;
>
> +}