Assert fails when `-contig` is specified in multi constraint graph

[gfaster]

The following graph fails an assert when compiled with assert=1:

% partition with this command:
% gpmetis -ptype=kway -ctype=shem -objtype=vol -contig -seed=125 -nooutput GRAPH_FILE 16
51 207 010 3
1 1 1 48 46 44 35 29 28 23 22 21 16
1 1 1 44 36 33 18
1 1 1 47 46 45 39 36 35 32 31 22 9 7
1 1 1 45 39 34 33 31 24 22 9
1 1 1 43 39 27 26 25 22 19 9 7
1 1 1 50 26 25 23 20 18 10
1 1 1 45 39 35 32 31 23 22 18 8 5 3
1 1 1 51 33 28 27 22 19 7
1 1 1 51 50 48 35 32 29 24 22 20 14 11 10 5 4 3
1 1 1 45 39 35 22 21 16 9 6
1 1 1 39 32 27 9
1 1 1 50 39 36 34 33
1 1 1 50 42 40 28 26 17 14
1 1 1 45 35 13 9
1 1 1 48 43 42 35 32 31 22 21 16
1 1 1 51 50 37 33 27 15 10 1
1 1 1 43 41 33 31 26 21 20 18 13
1 1 1 47 45 44 27 22 19 17 7 6 2
1 1 1 48 47 45 43 25 24 21 18 8 5
1 1 1 42 40 17 9 6
1 1 1 50 47 46 45 28 19 17 15 10 1
1 1 1 51 47 41 39 30 29 18 15 10 9 8 7 5 4 3 1
1 1 1 47 27 26 7 6 1
1 1 1 41 39 38 35 32 31 25 19 9 4
1 1 1 49 45 41 38 32 24 19 6 5
1 1 1 36 34 32 23 17 13 6 5
1 1 1 46 44 39 23 18 16 11 8 5
1 1 1 51 50 31 21 13 8 1
1 1 1 50 45 38 33 30 22 9 1
1 1 1 37 32 29 22
1 1 1 44 28 24 17 15 7 4 3
1 1 1 51 30 26 25 24 15 11 9 7 3
1 1 1 47 43 29 17 16 12 8 4 2
1 1 1 50 48 42 26 12 4
1 1 1 50 47 45 43 37 24 15 14 10 9 7 3 1
1 1 1 42 26 12 3 2
1 1 1 35 30 16
1 1 1 40 29 25 24
1 1 1 49 46 27 24 22 12 11 10 7 5 4 3
1 1 1 44 42 38 20 13
1 1 1 48 46 45 43 25 24 22 17
1 1 1 50 45 40 36 34 20 15 13
1 1 1 41 35 33 19 17 15 5
1 1 1 46 40 31 27 18 2 1
1 1 1 42 41 35 29 25 21 19 18 14 10 7 4 3
1 1 1 50 44 41 39 27 21 3 1
1 1 1 51 48 35 33 23 22 21 19 18 3
1 1 1 47 41 34 19 15 9 1
1 1 1 39 25
1 1 1 51 46 42 35 34 29 28 21 16 13 12 9 6
1 1 1 50 47 32 28 22 16 9 8

the error in question:

***ASSERTION failed on line 694 of file [...]/libmetis/contig.c: ComputeCut(graph, where) == graph->mincut

[gfaster]

Removing this assert causes later asserts to fail, so this appears to be significant