Minor - P4 WT_CURSOR.reconfigure doesn't initialize call API information.
If you assert in __wt_txn_context_prepare_check that WT_SESSION.name is non-NULL, and run test_prepare03, you get this stack:
#3 0x00000008045686e2 in __wt_abort (session=0x807a48598)
at src/os_common/os_abort.c:27
#4 0x00000008045c372e in __wt_assert (session=0x807a48598, error=0,
file_name=0x8046005f7 "__wt_txn_context_prepare_check", line_number=200,
fmt=0x8045fe256 "%s") at src/support/err.c:512
#5 0x000000080450fe72 in __wt_txn_context_prepare_check (session=0x807a48598)
at misc.i:200
#6 0x0000000804514f6b in __wt_cursor_reconfigure (cursor=0x807478300,
config=0x0) at src/cursor/cur_std.c:913