undo "delete tree" crashes arb

[westram]

reproduce:

• start demo.arb
• start Tree/TreeAdmin?
• click 'Delete'
• click 'Undo' in main window

#0  strncat (s1=0x7b4bd7 " ", s2=0x0, n=800) at strncat.c:52
#1  0x00007ffff7b97704 in GBT_tree_info_string(GBDATA*, char const*, int) () from /home/ralf/ARB-bilbo/ARB.trunk.test.NDEBUG/lib/libARBDB.so
#2  0x00007ffff73e26b4 in AWT_tree_selection::fill() () from /home/ralf/ARB-bilbo/ARB.trunk.test.NDEBUG/lib/libAWT.so
#3  0x00007ffff71749da in AW_selection::refresh() () from /home/ralf/ARB-bilbo/ARB.trunk.test.NDEBUG/lib/libWINDOW.so
#4  0x00007ffff7b7414d in gb_pending_callbacks::call_and_forget(GB_CB_TYPE) () from /home/ralf/ARB-bilbo/ARB.trunk.test.NDEBUG/lib/libARBDB.so
#5  0x00007ffff7b74297 in GB_MAIN_TYPE::call_pending_callbacks() () from /home/ralf/ARB-bilbo/ARB.trunk.test.NDEBUG/lib/libARBDB.so
#6  0x00007ffff7b78bef in GB_MAIN_TYPE::commit_transaction() () from /home/ralf/ARB-bilbo/ARB.trunk.test.NDEBUG/lib/libARBDB.so
#7  0x00007ffff7b842f1 in GB_undo(GBDATA*, GB_UNDO_TYPE) () from /home/ralf/ARB-bilbo/ARB.trunk.test.NDEBUG/lib/libARBDB.so
#8  0x00000000004382f1 in NT_undo_cb(AW_window*, long, long) ()
#9  0x00007ffff715bfe7 in AW_cb::run_callbacks() () from /home/ralf/ARB-bilbo/ARB.trunk.test.NDEBUG/lib/libWINDOW.so
#10 0x00007ffff717af28 in AW_server_callback(_WidgetRec*, void*, void*) () from /home/ralf/ARB-bilbo/ARB.trunk.test.NDEBUG/lib/libWINDOW.so
#11 0x00007ffff6814c7f in XtCallCallbackList () from /usr/lib/libXt.so.6
#12 0x00007ffff6d5ab05 in ?? () from /usr/lib/libXm.so.3
#13 0x00007ffff684bb2d in ?? () from /usr/lib/libXt.so.6
#14 0x00007ffff684c395 in _XtTranslateEvent () from /usr/lib/libXt.so.6
#15 0x00007ffff6822f5b in XtDispatchEventToWidget () from /usr/lib/libXt.so.6
#16 0x00007ffff68237a3 in ?? () from /usr/lib/libXt.so.6
#17 0x00007ffff6822714 in XtDispatchEvent () from /usr/lib/libXt.so.6
#18 0x00007ffff68228bb in XtAppMainLoop () from /usr/lib/libXt.so.6
#19 0x0000000000446e66 in startup_gui(NtreeCommandLine&, ARB_ERROR&) ()
#20 0x0000000000447400 in ARB_main(int, char**) ()
#21 0x00007ffff57a1c8d in __libc_start_main (main=<value optimized out>, argc=<value optimized out>, ubp_av=<value optimized out>, init=<value optimized out>, fini=<value optimized out>, rtld_fini=<value optimized out>, stack_end=0x7fffffffe288) at libc-start.c:226
#22 0x0000000000425b59 in _start ()

[westram]

might get fixed by #496