SerialPortInfoWinBase.cpp _T() cannot convert 'const char*' to 'LPCWSTR

[itas109]

Describe the bug
SerialPortInfoWinBase.cpp _T() cannot convert 'const char*' to 'LPCWSTR

SerialPortInfoWinBase.cpp:93:107: error: cannot convert 'const char*' to 'LPCWSTR {aka const wchar_t*}' for argument '2' to 'LONG RegQueryValueExW(HKEY, LPCWSTR, LPDWORD, LPDWORD, LPBYTE, LPDWORD)'

RegQueryValueEx(hDevKey, _T("PortName"), NULL, NULL, (BYTE*)portName, &dwCount);

Desktop (please complete the following information):

• OS: Win7 Ultimate 64bit
• Compiler: QT 5.6.3 MinGW 4.9.2 (32-bit)
• Version: 4.0.3.200429

[itas109]

RegQueryValueEx(hDevKey, _T("PortName"), NULL, NULL, (BYTE*)portName, &dwCount);

MinGW 4.9.2 (32-bit) file tchar.h

#ifdef _UNICODE
...
#define __T(x) L##x
...
#else
...
#define __T(x) x
...
#endif

but, QT defined UNICODE( not _UNICODE)

so, denfine _UNICODE can solve this problem