#343 NArchive::NCab::CHandler::Open needs to check callback existence

[ciel]

see attached patch

[ciel]

sorry file name was wrong

--- a/7z1900-src/CPP/7zip/Archive/Cab/CabHandler.cpp
+++ b/7z1900-src/CPP/7zip/Archive/Cab/CabHandler.cpp

[Igor Pavlov]

Thanks for report.
Also another line below must be fixed:

RINOK(callback->SetCompleted(&numItems, NULL));