FindShortestPath failing with All even when GraphDistanceMatrix succeeds

Question

Shortest Path routines are commonly used within more complex optimization methods that work to ensure there are no negative cycles even when there are negative weight edges. Often there are 0 weight cycles, which raises obvious precision issues. But we would expect some consistency in how those are handled.

Here's a case where FindShortestPath[graph, i, 1] succeeds for all vertices i, GraphDistanceMatrix[graph] succeeds, but FindShortestPath[graph, All, 1] fails.

Any thoughts on why this occurs?

graph = 
   Graph[List[DirectedEdge[2, 4], DirectedEdge[1, 2], DirectedEdge[3, 3], 
                    DirectedEdge[4, 4], DirectedEdge[2, 1], DirectedEdge[1, 1], 
                    DirectedEdge[3, 2], DirectedEdge[4, 2]], 
               Rule[EdgeWeight,
 List[
 Rule[DirectedEdge[1,2], -0.01091784833945534840442836344586391687`18.130853970762928],
 Rule[DirectedEdge[2,1], 0.01091784836435579080721835523637724884`18.13083252738191], 
 Rule[DirectedEdge[1,3], 0.05856056395863386924668038076285580822`19.161321314068676], 
 Rule[DirectedEdge[3,1], -0.0392119168158420557184565732775045898`18.98709027996202], 
 Rule[DirectedEdge[1,4], 0.04898657905283750869314558522357293851`18.57086486584574], 
 Rule[DirectedEdge[4,1], -0.27016936835296771144136460026425837676`18.996775256537283], 
 Rule[DirectedEdge[2,3], 0.05060741925025987557014918123693047741`19.097959401559123], 
 Rule[DirectedEdge[3,2], -0.05060741924007811018893480135813097558`19.097498250879173], 
 Rule[DirectedEdge[2,4], 0.28828503026977619631171524636984558167`18.63396198032326], 
 Rule[DirectedEdge[4,2], -0.28828503026977619631171524636984558168`18.778871438162028], 
 Rule[DirectedEdge[3,4], 0.06260132441378883638716246196054271422`24.48295254456055], 
 Rule[DirectedEdge[4,3], -0.13558038477833085576576255146647013499`18.744066844400113]]]]

There are no negative weight cycles:

GraphDistanceMatrix[graph]

yields {{0., 0.288285, 0.0109178, [Infinity]}, {-0.288285, 0., -0.277367, [Infinity]}, {-0.0109178, 0.277367, 0., [Infinity]}, {-0.0506074, 0.237678, -0.0396896, 0.}}

And FindShortestPath correctly handles vertex to vertex requests: FindShortestPath[graph, 4, 1] yields {4, 2, 1} FindShortestPath[graph, 3, 1] yields {3, 2, 1} FindShortestPath[graph, 2, 1] yields {2, 1} But

pathfunc = FindShortestPath[graph, All, 1];
pathfunc[4]

yields {} as does pathfunc[i] with any other vertex i