Slightly more robust error checking in SolidModel to avoid dereferencing a NULL pointer.
Slightly more robust error checking in SolidModel to avoid dereferencing a NULL pointer.

Refs #2379.

nuclear-wizard/moose,raghavaggarwal/moose,jinmm1992/moose,cpritam/moose,YaqiWang/moose,dschwen/moose,roystgnr/moose,jasondhales/moose,shanestafford/moose,jhbradley/moose,stimpsonsg/moose,jessecarterMOOSE/moose,shanestafford/moose,zzyfisherman/moose,andrsd/moose,YaqiWang/moose,mellis13/moose,sapitts/moose,idaholab/moose,giopastor/moose,danielru/moose,raghavaggarwal/moose,jiangwen84/moose,jessecarterMOOSE/moose,cpritam/moose,apc-llc/moose,zzyfisherman/moose,dschwen/moose,markr622/moose,WilkAndy/moose,andrsd/moose,danielru/moose,cpritam/moose,Chuban/moose,jiangwen84/moose,idaholab/moose,capitalaslash/moose,jhbradley/moose,mellis13/moose,adamLange/moose,dschwen/moose,cpritam/moose,lindsayad/moose,wgapl/moose,roystgnr/moose,waxmanr/moose,WilkAndy/moose,xy515258/moose,WilkAndy/moose,milljm/moose,capitalaslash/moose,jessecarterMOOSE/moose,jinmm1992/moose,waxmanr/moose,Chuban/moose,harterj/moose,shanestafford/moose,katyhuff/moose,raghavaggarwal/moose,friedmud/moose,WilkAndy/moose,permcody/moose,zzyfisherman/moose,backmari/moose,roystgnr/moose,YaqiWang/moose,sapitts/moose,roystgnr/moose,mellis13/moose,Chuban/moose,jhbradley/moose,roystgnr/moose,andrsd/moose,idaholab/moose,xy515258/moose,roystgnr/moose,giopastor/moose,liuwenf/moose,zzyfisherman/moose,tonkmr/moose,backmari/moose,tonkmr/moose,capitalaslash/moose,stimpsonsg/moose,jessecarterMOOSE/moose,liuwenf/moose,wgapl/moose,bwspenc/moose,joshua-cogliati-inl/moose,kasra83/moose,danielru/moose,lindsayad/moose,adamLange/moose,permcody/moose,bwspenc/moose,bwspenc/moose,jinmm1992/moose,stimpsonsg/moose,yipenggao/moose,YaqiWang/moose,apc-llc/moose,raghavaggarwal/moose,nuclear-wizard/moose,yipenggao/moose,bwspenc/moose,cpritam/moose,permcody/moose,sapitts/moose,liuwenf/moose,shanestafford/moose,milljm/moose,friedmud/moose,joshua-cogliati-inl/moose,jiangwen84/moose,SudiptaBiswas/moose,backmari/moose,joshua-cogliati-inl/moose,tonkmr/moose,idaholab/moose,capitalaslash/moose,SudiptaBiswas/moose,harterj/moose,jbair34/moose,SudiptaBiswas/moose,lindsayad/moose,apc-llc/moose,permcody/moose,zzyfisherman/moose,andrsd/moose,idaholab/moose,xy515258/moose,cpritam/moose,tonkmr/moose,jhbradley/moose,shanestafford/moose,kasra83/moose,katyhuff/moose,waxmanr/moose,yipenggao/moose,andrsd/moose,roystgnr/moose,SudiptaBiswas/moose,mellis13/moose,yipenggao/moose,tonkmr/moose,sapitts/moose,adamLange/moose,wgapl/moose,giopastor/moose,jinmm1992/moose,laagesen/moose,dschwen/moose,friedmud/moose,jbair34/moose,sapitts/moose,katyhuff/moose,nuclear-wizard/moose,lindsayad/moose,stimpsonsg/moose,jasondhales/moose,liuwenf/moose,laagesen/moose,harterj/moose,lindsayad/moose,milljm/moose,milljm/moose,liuwenf/moose,zzyfisherman/moose,xy515258/moose,markr622/moose,bwspenc/moose,adamLange/moose,jbair34/moose,jbair34/moose,katyhuff/moose,tonkmr/moose,jasondhales/moose,friedmud/moose,jiangwen84/moose,SudiptaBiswas/moose,apc-llc/moose,harterj/moose,jessecarterMOOSE/moose,kasra83/moose,backmari/moose,jasondhales/moose,Chuban/moose,giopastor/moose,WilkAndy/moose,wgapl/moose,markr622/moose,waxmanr/moose,joshua-cogliati-inl/moose,WilkAndy/moose,harterj/moose,danielru/moose,laagesen/moose,liuwenf/moose,laagesen/moose,shanestafford/moose,markr622/moose,dschwen/moose,nuclear-wizard/moose,kasra83/moose,laagesen/moose,milljm/moose