Number: 1355
Title: flat edge bug
Submitter: John Ellson
Date: Mon May 12 18:10:14 2008
Subsys: Dot
Version: 2.18
System: *-*-
Severity: minor
Problem:
This bug report from a Ubuntu (https://bugs.launchpad.net/ubuntu/+source/graphviz/+bug/229516) with graphviz-2.16 user contains an unterminated graph. But if I terminate the graph (attached) I can reproduce the problem with graphviz-2.18.

Its a flat-edge problem.

Most of the virtual nodes in the rank are ok, but the pointer is corrupted to the one that results in the crash.

Not sure where these arrays of vnodes are created?


(gdb) p r
$19 = 1
(gdb) p i
$20 = 3
(gdb) p g->u.rank[1].n
$21 = 7
(gdb) p g->u.rank[r].v[i]
$22 = (node_t *) 0x6ae0d0
(gdb) c
Continuing.

Breakpoint 1, flat_reorder (g=0x614a50) at mincross.c:981 981 MARK(GD_rank(g)[r].v[i]) = FALSE; (gdb) p r $23 = 1 (gdb) p i $24 = 4 (gdb) p g->u.rank[r].v[i] $25 = (node_t *) 0x1006ae320 (gdb) c Continuing.

Program received signal SIGSEGV, Segmentation fault. flat_reorder (g=0x614a50) at mincross.c:981 981 MARK(GD_rank(g)[r].v[i]) = FALSE; (gdb) p g->u.minrank $26 = 0 (gdb) p g->u.maxrank $27 = 2 (gdb) p g->u.rank[r].n $28 = 7 (gdb)

Input graph: b1355.dot
Owner: *
Status: *