Invalid read in plugin-libevent.c

In plugin-libevent.c, event_new() mallocs a "struct event", which is not initialized, then passes it to event_assign(), which passes it into event_base_set(), causing an invalid read. We picked it up during a valgrind run of our program.

See lines 47 - 78 here: https://github.com/couchbase/libcouchbase/blob/master/plugins/io/libevent/plugin-libevent.c

Proposed patch:

Index: libcouchbase/src/plugin-libevent.c
===================================================================
— libcouchbase/src/plugin-libevent.c (revision 16)
+++ libcouchbase/src/plugin-libevent.c (working copy)
@@ -47,7 +47,6 @@
event_callback_fn callback,
void *arg)

{ - event_base_set(base, ev); ev->ev_callback = callback; ev->ev_arg = arg; ev->ev_fd = fd; @@ -56,6 +55,7 @@ ev->ev_flags = EVLIST_INIT; ev->ev_ncalls = 0; ev->ev_pncalls = NULL; + event_base_set(base, ev); return 0; }