When running fc_sort on an empty context file, this program uses uninitialized
pointers when accessing to the elements of a list. On my system, it goes in a
very long loop (maybe infinite) because uninitialized fields in malloc'ed
structures happen to contain valid pointers in the heap.
This patch fixes this bug by initializing ->next and ->data fields before they
may be read.
Nicolas Iooss
Chris PeBenito