add test cases for zero-weight edges in sparse representation
add test cases for zero-weight edges in sparse representation

anntzer/scipy,scipy/scipy,grlee77/scipy,vigna/scipy,perimosocordiae/scipy,ilayn/scipy,jamestwebber/scipy,mdhaber/scipy,arokem/scipy,anntzer/scipy,jor-/scipy,jor-/scipy,scipy/scipy,e-q/scipy,matthew-brett/scipy,grlee77/scipy,tylerjereddy/scipy,pizzathief/scipy,Eric89GXL/scipy,rgommers/scipy,rgommers/scipy,aarchiba/scipy,perimosocordiae/scipy,jamestwebber/scipy,endolith/scipy,vigna/scipy,Stefan-Endres/scipy,tylerjereddy/scipy,ilayn/scipy,nmayorov/scipy,aeklant/scipy,pizzathief/scipy,endolith/scipy,aeklant/scipy,person142/scipy,ilayn/scipy,aarchiba/scipy,anntzer/scipy,person142/scipy,e-q/scipy,rgommers/scipy,jor-/scipy,Stefan-Endres/scipy,anntzer/scipy,jor-/scipy,scipy/scipy,rgommers/scipy,matthew-brett/scipy,zerothi/scipy,endolith/scipy,nmayorov/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,endolith/scipy,matthew-brett/scipy,Eric89GXL/scipy,vigna/scipy,jamestwebber/scipy,zerothi/scipy,andyfaff/scipy,nmayorov/scipy,arokem/scipy,ilayn/scipy,aeklant/scipy,jamestwebber/scipy,pizzathief/scipy,scipy/scipy,perimosocordiae/scipy,anntzer/scipy,aarchiba/scipy,tylerjereddy/scipy,mdhaber/scipy,andyfaff/scipy,Eric89GXL/scipy,endolith/scipy,mdhaber/scipy,aarchiba/scipy,scipy/scipy,andyfaff/scipy,person142/scipy,jor-/scipy,grlee77/scipy,endolith/scipy,tylerjereddy/scipy,anntzer/scipy,tylerjereddy/scipy,e-q/scipy,andyfaff/scipy,grlee77/scipy,person142/scipy,ilayn/scipy,e-q/scipy,mdhaber/scipy,vigna/scipy,grlee77/scipy,WarrenWeckesser/scipy,aeklant/scipy,perimosocordiae/scipy,aarchiba/scipy,arokem/scipy,WarrenWeckesser/scipy,zerothi/scipy,mdhaber/scipy,scipy/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,rgommers/scipy,Eric89GXL/scipy,Stefan-Endres/scipy,Eric89GXL/scipy,WarrenWeckesser/scipy,mdhaber/scipy,ilayn/scipy,nmayorov/scipy,pizzathief/scipy,vigna/scipy,matthew-brett/scipy,arokem/scipy,perimosocordiae/scipy,aeklant/scipy,jamestwebber/scipy,perimosocordiae/scipy,matthew-brett/scipy,nmayorov/scipy,e-q/scipy,zerothi/scipy,pizzathief/scipy,Eric89GXL/scipy,andyfaff/scipy,arokem/scipy,person142/scipy,zerothi/scipy,zerothi/scipy,andyfaff/scipy