If init fails halfway through it will call the destroy function,
which needs some coherent stuff filled.
Allocate with calloc and fill in what cannot fail first
Found through static analysis.
size_t/ssize_t are 8 bytes on 64bit systems, so use the proper size to
transmit that information.
This could lead to ridiculously large alloc as len is not initialized to zero
Found through static analysis
Dominique Martinet
Geoff Greer
Drew DeVault