Bug in Graph() when input is a weighted matrix

[nathanncohen]

As reported in [1], the following code produces an exception :

sage: B = {0:{1:2,2:5,3:4},1:{2:2,4:7},2:{3:1,4:4,5:3},3:{5:4},4:{5:1,6:5},5:{6:7}} 
sage: grafo3 = Graph(B,weighted=True) 
sage: matad = grafo3.weighted_adjacency_matrix() 
sage: grafo4 = Graph(matad,format = "adjacency_matrix", weighted=True) 
sage: grafo4.shortest_path(0,6,by_weight=True)

This, because Sage has some problems understanding that the graph is not a multigraph...

[1] https://groups.google.com/forum/?fromgroups=#!topic/sage-support/rIpMl1u7VXE

CC: @fchapoton

Component: graph theory

Author: Nathann Cohen

Reviewer: Frédéric Chapoton

Merged: sage-5.7.beta1

Issue created by migration from https://trac.sagemath.org/ticket/13919

[fchapoton]

comment:2

Please correct the failing doctest, otherwise it's ok

[nathanncohen]

Attachment: trac_13919.patch.gz

[nathanncohen]

comment:3

Updated !

Nathann

[fchapoton]

comment:4

ok, let it go. Positive review !

[jdemeyer]

Reviewer: Frédéric Chapoton

[jdemeyer]

Merged: sage-5.7.beta1