V3 Intermittent segfault on select * from graph after manipulations of backing table

[Andrew McDonnell]

Could be related to bug #1195735
Could be related to bug #796647

See regression_xxx.test for limited example.

Attached a (not committed copy of) version of basic.test which triggers this

debian squeeze amd64 boost_1.42

If a select SLEEP(1) is inserted at a lucky spot, the segfault doesn't occur...

[Andrew McDonnell (andymc73)]

This version doesnt crash

[Andrew McDonnell (andymc73)]

Crash is guaranteed no debug version, but might only happen sometimes on normal build

Stack dump when it does:

#2 <signal handler called>
#3 intrusive_ptr_release (ptr=<optimized out>) at /home/andrew/develop/maria/repo/oqgraph-dev/storage/oqgraph/oqgraph_thunk.h:132
#4 ~intrusive_ptr (this=<optimized out>, __in_chrg=<optimized out>) at /usr/include/boost/smart_ptr/intrusive_ptr.hpp:101
#5 operator= (rhs=<optimized out>, this=<optimized out>) at /usr/include/boost/smart_ptr/intrusive_ptr.hpp:133
#6 operator= (this=<optimized out>) at /home/andrew/develop/maria/repo/oqgraph-dev/storage/oqgraph/oqgraph_thunk.h:58
#7 operator= (this=<optimized out>) at /home/andrew/develop/maria/repo/oqgraph-dev/storage/oqgraph/oqgraph_thunk.h:68
#8 operator= (this=<optimized out>) at /home/andrew/develop/maria/repo/oqgraph-dev/storage/oqgraph/graphcore.cc:136
#9 open_query::edges_cursor::current (this=0x1caa7a0, ref=...) at /home/andrew/develop/maria/repo/oqgraph-dev/storage/oqgraph/graphcore.cc:316
#10 0x00007fe58275ae50 in open_query::oqgraph::row_ref (this=<optimized out>, ref_ptr=0x1cb14e0) at /home/andrew/develop/maria/repo/oqgraph-dev/storage/oqgraph/graphcore.cc:948
#11 0x00007fe582758fcc in ha_oqgraph::index_read (this=0x1cad470, buf=0x1cae5f0 "\377", key=0x1cb4f68 "", key_len=35, find_flag=HA_READ_KEY_EXACT) at /home/andrew/develop/maria/repo/oqgraph-dev/storage/oqgraph/ha_oqgraph.cc:748
#12 0x00000000006a0815 in handler::ha_index_read_map (this=0x1cad470, buf=0x1cae5f0 "\377", key=0x1cb4f68 "", keypart_map=1, find_flag=HA_READ_KEY_EXACT) at /home/andrew/develop/maria/repo/oqgraph-dev/sql/handler.cc:2447

[Andrew McDonnell (andymc73)]

This seems to be not happening now, unsure whether because currently testing in Wheezy or because lp:maria/10.0 lastest changes merged; will review soon

[Andrew McDonnell (andymc73)]

Or could be same fix as bug 1195735

Regressoin tst apssing now so closing for now