#155 AVOPCOMP SIGSEGV

[seismick]

AVOPCOMP works when only the eight-trace standard suite is input. But when velocity trace and seismic traces are added, it aborts with SIGSEGV on first gather. Found that the problem is that variable v_ptr was not initialised. It is used as array index, and so some large random number results in attempt to access invalid memory. The velocity trace is supposed to be the ninth trace in the input gather, and setting v_ptr to the index of the actual velocity trace fixes the problem.