decklink: Fix broken COM string conversion

WideCharToMultiByte return is the string length without null terminate
character if passed "cchWideChar" does not include the null terminate
character size. Instead of passing the exact string length, pass -1 so that
the API can understand the input string is null terminated already and
returned value from the API includes the character.

Fixes: https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/3023
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/5444>
This commit is contained in:
Seungha Yang 2023-10-09 19:09:15 +09:00
parent c020dab393
commit 3536b7f3a6

View file

@ -37,19 +37,17 @@
#define COMSTR_T BSTR
#define CONVERT_COM_STRING(s) G_STMT_START { \
BSTR _s = (BSTR)s; \
int _s_length = ::SysStringLen(_s); \
int _length = ::WideCharToMultiByte(CP_ACP, 0, (wchar_t*)_s, _s_length, NULL, 0, NULL, NULL); \
int _length = ::WideCharToMultiByte(CP_ACP, 0, (wchar_t*)_s, -1, NULL, 0, NULL, NULL); \
s = (char *) malloc(_length); \
::WideCharToMultiByte(CP_ACP, 0, (wchar_t*)_s, _s_length, s, _length, NULL, NULL); \
::WideCharToMultiByte(CP_ACP, 0, (wchar_t*)_s, -1, s, _length, NULL, NULL); \
::SysFreeString(_s); \
} G_STMT_END
#define FREE_COM_STRING(s) free(s);
#define CONVERT_TO_COM_STRING(s) G_STMT_START { \
char * _s = (char *)s; \
int _s_length = strlen((char*)_s); \
int _length = ::MultiByteToWideChar(CP_ACP, 0, (char*)_s, _s_length, NULL, 0); \
int _length = ::MultiByteToWideChar(CP_ACP, 0, (char*)_s, -1, NULL, 0); \
s = ::SysAllocStringLen(NULL, _length); \
::MultiByteToWideChar(CP_ACP, 0, (char*)_s, _s_length, s, _length); \
::MultiByteToWideChar(CP_ACP, 0, (char*)_s, -1, s, _length); \
g_free(_s); \
} G_STMT_END
#elif defined(__APPLE__)