[Ocaml-lib-devel] segfault in GC when creating a DynArray of size zero

[Janne H. <ja...@hy...>]

The following test case in the testing suite causes a segfault in 
garbage collection:

--cut--
(* NOTE this is a copy of Skaller's trivial DynArray test.  Apparently
    he hit the nail on the head with the first try, since test_triv causes a
    segfault if you run Gc.major () after test_triv.  If you change the
    initial size of the DynArray to one or bigger, the crash does not
    occur. *)

open DynArray

let test_triv () =
   let a = make 0 in (* ZERO here causes a segfault later in GC??? *)
   let b = copy a in
   assert (length a == 0);
   assert (length b == 0);
   Gc.major ()
--cut--

It is enabled in the testing suite.  If you want to run only this case, 
build mktest and run:

$ ./mktest --author=jh --module=DynArray
$ ./extlib_test

Even though I didn't try, the crash should be reproducible outside of 
the testing suite.  Tested with the latest CVS version of extlib.

ciao,
janne