BUG: fix splprep seg fault
BUG: fix splprep seg fault

Fixes random seg faults of the splprep routing caused by copying data into a zero sized array. See #7395

Eric89GXL/scipy,zerothi/scipy,scipy/scipy,grlee77/scipy,zerothi/scipy,Stefan-Endres/scipy,andyfaff/scipy,vigna/scipy,ilayn/scipy,e-q/scipy,scipy/scipy,andyfaff/scipy,Eric89GXL/scipy,e-q/scipy,anntzer/scipy,zerothi/scipy,mdhaber/scipy,vigna/scipy,e-q/scipy,rgommers/scipy,endolith/scipy,anntzer/scipy,tylerjereddy/scipy,scipy/scipy,perimosocordiae/scipy,perimosocordiae/scipy,grlee77/scipy,matthew-brett/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,e-q/scipy,mdhaber/scipy,matthew-brett/scipy,Eric89GXL/scipy,anntzer/scipy,grlee77/scipy,anntzer/scipy,Stefan-Endres/scipy,andyfaff/scipy,tylerjereddy/scipy,tylerjereddy/scipy,endolith/scipy,matthew-brett/scipy,ilayn/scipy,rgommers/scipy,mdhaber/scipy,WarrenWeckesser/scipy,Eric89GXL/scipy,Stefan-Endres/scipy,mdhaber/scipy,rgommers/scipy,Eric89GXL/scipy,endolith/scipy,scipy/scipy,endolith/scipy,rgommers/scipy,nmayorov/scipy,andyfaff/scipy,tylerjereddy/scipy,perimosocordiae/scipy,Stefan-Endres/scipy,anntzer/scipy,WarrenWeckesser/scipy,WarrenWeckesser/scipy,vigna/scipy,mdhaber/scipy,nmayorov/scipy,vigna/scipy,matthew-brett/scipy,perimosocordiae/scipy,perimosocordiae/scipy,endolith/scipy,ilayn/scipy,tylerjereddy/scipy,ilayn/scipy,zerothi/scipy,grlee77/scipy,WarrenWeckesser/scipy,zerothi/scipy,WarrenWeckesser/scipy,andyfaff/scipy,scipy/scipy,zerothi/scipy,rgommers/scipy,Eric89GXL/scipy,mdhaber/scipy,andyfaff/scipy,Stefan-Endres/scipy,e-q/scipy,anntzer/scipy,ilayn/scipy,perimosocordiae/scipy,nmayorov/scipy,grlee77/scipy,matthew-brett/scipy,nmayorov/scipy,vigna/scipy,endolith/scipy,scipy/scipy,nmayorov/scipy,ilayn/scipy