isisd: Segmentation fault on isis daemon fixes

isisd: Segmentation fault on isis daemon fixes

I have a fix for 2 segmentation fault scenarios on the isis daemon:
1. When running a command "isis passive" on an interface in the
following context:
"end"
"configure terminal "
"interface dummy0"
"isis passive"
The trace back collected:
isis_adjacency.c:521
family=2,
     root_sysid=0x20aee6d0 "", parent=0x20af4d68) at isis_spf.c:999
sysid=0x20aee6d0 "")
     at isis_spf.c:1217
isis_spf.c:1372
isis_lsp.c:416
isis_lsp.c:1660
isis_main.c:368

The fix location:
file name: isisd/isis_adjacency.c
routine name: isis_adj_build_up_list

2. When deleting the existing isis router instance:
"end"
"configure terminal "
"no router isis DEAD"

The fix location:
isisd/isis_events.c, routine circuit_resign_level
isisd/isis_lsp.c, routine lsp_destroy
isisd/isis_route.c, isis_route_validate

The trace back collection:
"DEAD") at isisd.c:252
argc=1, argv=0xbfc39054) at isisd.c:1520
vty=0x20d6f528, cmd=0x0) at command.c:2121
cmd=0x0, vtysh=0) at command.c:2155
isis DEAD") at vty.c:433
isis_main.c:368

and

"DEAD") at isisd.c:260
argc=1, argv=0xbfd6cf54) at isisd.c:1520
vty=0x208cb528, cmd=0x0) at command.c:2121
cmd=0x0, vtysh=0) at command.c:2155
isis DEAD") at vty.c:433
isis_main.c:368

The patch is included.

patchwork #833: http://patchwork.quagga.net/patch/833/