Bug introduced in 9.0 or earlier and fixed in 12.0

Test the below function:

Func[g_] := 
Module[{G, vl, vdG},    
G = g;    
While[VertexCount[G] != 0,  
vl = VertexList[G];  
vdG = Map[VertexDegree[G, #] &, vl];     
vl = Extract[vl, Position[vdG, Max[vdG]]];     
G = VertexDelete[G, vl[[1]]];


While[g = RandomGraph[
   BernoulliGraphDistribution[ RandomInteger[{50, 100}], 
    RandomReal[]]]; Func[g]; True]

The same if Module[{G=g,...

Good if G = Graph[VertexList[g], EdgeList[g]];

Is there any method to copy a graph efficiently?

  • $\begingroup$ You can format inline code and code blocks by selecting the code and clicking the {} button above the edit window. The edit window help button ? is also useful for learning how to format your questions and answers. You may also find this meta Q&A helpful $\endgroup$
    – Michael E2
    Sep 3, 2016 at 0:34
  • $\begingroup$ I tried to edit the code to make a little more sense. Please role back either Micheal or ZYX if you don't approve. $\endgroup$
    – William
    Sep 3, 2016 at 0:50
  • 2
    $\begingroup$ Confirmed. Please report bugs to Wolfram Support. $\endgroup$
    – Szabolcs
    Sep 3, 2016 at 10:12
  • $\begingroup$ @Szabolcs 11.2 is out ?! $\endgroup$
    – gwr
    Sep 15, 2017 at 9:44
  • $\begingroup$ @gwr blog.wolfram.com/2017/09/14/… $\endgroup$
    – Szabolcs
    Sep 15, 2017 at 9:46

1 Answer 1


I can reproduce the problem. A more minimal example is


 VertexDelete[RandomGraph[BernoulliGraphDistribution[50, 0.5]], 1];
 a = MemoryInUse[];

Please report this to Wolfram Support.


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