[tkreuzer] 26929: undocumented behavior of LoadStringW: If nBufferMax is 0, LoadStringW will copy a pointer to the in-memory image of the string to the specified buffer and return the length of the string in WCHARs.
Author: tkreuzer Date: Mon May 28 04:35:55 2007 New Revision: 26929
URL: http://svn.reactos.org/svn/reactos?rev=26929&view=rev Log: undocumented behavior of LoadStringW: If nBufferMax is 0, LoadStringW will copy a pointer to the in-memory image of the string to the specified buffer and return the length of the string in WCHARs.
Modified: trunk/reactos/dll/win32/user32/misc/resources.c
Modified: trunk/reactos/dll/win32/user32/misc/resources.c URL: http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/user32/misc/resou... ============================================================================== --- trunk/reactos/dll/win32/user32/misc/resources.c (original) +++ trunk/reactos/dll/win32/user32/misc/resources.c Mon May 28 04:35:55 2007 @@ -98,63 +98,71 @@ int nBufferMax ) { - UNICODE_STRING wstrResStr; - ANSI_STRING strBuf; - INT retSize; - - /* parameter validation */ - if - ( - (nBufferMax < 1) || - (IsBadWritePtr(lpBuffer, nBufferMax * sizeof(lpBuffer[0]))) - ) - { - SetLastError(ERROR_INVALID_PARAMETER); - return 0; - } - - /* get the UNICODE_STRING descriptor of the in-memory image of the string */ - if(!_InternalLoadString(hInstance, uID, &wstrResStr)) - /* failure */ - return 0; - - /* - convert the string. The Unicode string may be in UTF-16 (multi-byte), so we - don't alter wstrResStr.Length, and let RtlUnicodeStringToAnsiString truncate - it, if necessary - */ - strBuf.Length = 0; - strBuf.MaximumLength = nBufferMax * sizeof(CHAR); - strBuf.Buffer = lpBuffer; - - retSize = WideCharToMultiByte(CP_ACP, 0, wstrResStr.Buffer, wstrResStr.Length / sizeof(WCHAR), strBuf.Buffer, strBuf.MaximumLength, NULL, NULL); - - if(!retSize) - /* failure */ - return 0; - else - strBuf.Length = retSize; - - /* the ANSI string may not be null-terminated */ - if(strBuf.Length >= strBuf.MaximumLength) - { - /* length greater than the buffer? whatever */ - int nStringLen = strBuf.MaximumLength / sizeof(CHAR) - 1; - - /* zero the last character in the buffer */ - strBuf.Buffer[nStringLen] = 0; - - /* success */ - return nStringLen; - } - else - { - /* zero the last character in the string */ - strBuf.Buffer[strBuf.Length / sizeof(CHAR)] = 0; - - /* success */ - return strBuf.Length / sizeof(CHAR); - } + UNICODE_STRING wstrResStr; + ANSI_STRING strBuf; + INT retSize; + + /* parameter validation */ + if + ( + (nBufferMax < 1) || + (IsBadWritePtr(lpBuffer, nBufferMax * sizeof(lpBuffer[0]))) + ) + { + SetLastError(ERROR_INVALID_PARAMETER); + return 0; + } + + /* get the UNICODE_STRING descriptor of the in-memory image of the string */ + if(!_InternalLoadString(hInstance, uID, &wstrResStr)) + { + /* failure */ + return 0; + } + + /* + convert the string. The Unicode string may be in UTF-16 (multi-byte), so we + don't alter wstrResStr.Length, and let RtlUnicodeStringToAnsiString truncate + it, if necessary + */ + strBuf.Length = 0; + strBuf.MaximumLength = nBufferMax * sizeof(CHAR); + strBuf.Buffer = lpBuffer; + + retSize = WideCharToMultiByte(CP_ACP, 0, wstrResStr.Buffer, + wstrResStr.Length / sizeof(WCHAR), + strBuf.Buffer, strBuf.MaximumLength, NULL, NULL); + + if(!retSize) + { + /* failure */ + return 0; + } + else + { + strBuf.Length = retSize; + } + + /* the ANSI string may not be null-terminated */ + if(strBuf.Length >= strBuf.MaximumLength) + { + /* length greater than the buffer? whatever */ + int nStringLen = strBuf.MaximumLength / sizeof(CHAR) - 1; + + /* zero the last character in the buffer */ + strBuf.Buffer[nStringLen] = 0; + + /* success */ + return nStringLen; + } + else + { + /* zero the last character in the string */ + strBuf.Buffer[strBuf.Length / sizeof(CHAR)] = 0; + + /* success */ + return strBuf.Length / sizeof(CHAR); + } }
@@ -169,41 +177,55 @@ int nBufferMax ) { - UNICODE_STRING wstrResStr; - int nStringLen; - - /* parameter validation */ - if - ( - (nBufferMax < 1) || - (IsBadWritePtr(lpBuffer, nBufferMax * sizeof(lpBuffer[0]))) - ) - { - SetLastError(ERROR_INVALID_PARAMETER); - return 0; - } - - /* get the UNICODE_STRING descriptor of the in-memory image of the string */ - if(!_InternalLoadString(hInstance, uID, &wstrResStr)) - /* failure */ - return 0; - - /* get the length in characters */ - nStringLen = wstrResStr.Length / sizeof(WCHAR); - - /* the buffer must be enough to contain the string and the null terminator */ - if(nBufferMax < (nStringLen + 1)) - /* otherwise, the string is truncated */ - nStringLen = nBufferMax - 1; - - /* copy the string */ - memcpy(lpBuffer, wstrResStr.Buffer, nStringLen * sizeof(WCHAR)); - - /* null-terminate it */ - lpBuffer[nStringLen] = 0; - - /* success */ - return nStringLen; + UNICODE_STRING wstrResStr; + int nStringLen; + + /* parameter validation */ + if + ( + (nBufferMax < 1) || + ((nBufferMax > 0) && IsBadWritePtr(lpBuffer, nBufferMax * sizeof(lpBuffer[0]))) || + /* undocumented: If nBufferMax is 0, LoadStringW will copy a pointer to the + in-memory image of the string to the specified buffer and return the length + of the string in WCHARs */ + ((nBufferMax == 0) && IsBadWritePtr(lpBuffer, sizeof(lpBuffer))) + ) + { + SetLastError(ERROR_INVALID_PARAMETER); + return 0; + } + + /* get the UNICODE_STRING descriptor of the in-memory image of the string */ + if(!_InternalLoadString(hInstance, uID, &wstrResStr)) + { + /* failure */ + return 0; + } + + /* get the length in characters */ + nStringLen = wstrResStr.Length / sizeof(WCHAR); + + if (nBufferMax > 0) + { + /* the buffer must be enough to contain the string and the null terminator */ + if(nBufferMax < (nStringLen + 1)) + { + /* otherwise, the string is truncated */ + nStringLen = nBufferMax - 1; + } + + /* copy the string */ + memcpy(lpBuffer, wstrResStr.Buffer, nStringLen * sizeof(WCHAR)); + + /* null-terminate it */ + lpBuffer[nStringLen] = 0; + } + else + { + *((LPWSTR*)lpBuffer) = wstrResStr.Buffer; + } + /* success */ + return nStringLen; }
/* EOF */
-
tkreuzer＠svn.reactos.org