Fix a heap corruption when printing specific REG_MULTI_SZ values.

[Sebastian Lackner]

On 23.04.2016 11:56, Hugh McMaster wrote:
> On Saturday, 23 April 2016 3:35 AM, Sebastian Lackner wrote:
> 
>> The current calculation does not take the terminating \0 into account.
> 
>> -buffer = HeapAlloc(GetProcessHeap(), 0, tmp_size * 2);
>> +buffer = HeapAlloc(GetProcessHeap(), 0, tmp_size * 2 + sizeof(WCHAR));
> 
> Which particular cases cause the heap corruption?
> 
> --
> Hugh McMaster
> 

It happens for example with a string like L"\0\0\0\0". After stripping off
the last two "\0" the allocated memory will have a size of 4 characters,
but the code below writes 5 characters. You can also test with warn+heap
after creating such a registry key.