Problem 735

Summary:	giving NULL G4Material* to G4LogicalVolume silently crashes G4 during run initialization
Product:	Geant4	Reporter:	jasondet
Component:	geometry/management	Assignee:	Gabriele Cosmo <Gabriele.Cosmo>
Status:	RESOLVED FIXED
Severity:	normal	CC:	asai
Priority:	P2
Version:	7.0
Hardware:	All
OS:	All

Description jasondet 2005-03-29 17:56:20 CEST

Dear Geant4 developers,

I have a G4 application in which I make a logical volume via a call like

myLVptr = new G4LogicalVolume(aSolid, G4Material::GetMaterial(matName), lvName);

Unfortunately, the string matName was not an existing G4Material, so
G4Material::GetMaterial(matName) quietly returned NULL. The G4LogicalVolume was
happy accepting this without any errors or warnings, but it eventually made my
program (silently) crash during G4RunManager::RunInitialization() when updating
the G4ProductionCutsTable.

I would like to suggest the following:

- Make G4LogicalVolume::SetMaterial(G4Material *pMaterial) check that pMaterial
is not NULL, and emit an error if it is. No logical volume should have a NULL
material pointer, right?

- Make G4Material::GetMaterial(G4String materialName) emit a warning message if
materialName is not the name of an existing material.

Thanks,
Jason

Comment 1 Michel.Maire 2005-03-30 11:22:59 CEST

done for what concern G4Material

Comment 2 Gabriele Cosmo 2005-04-04 07:44:59 CEST

NULL pointer to material must be allowed by G4LogicalVolume for the use-case of
readout and ghost (envelopes) geometries. The problem anyhow exists since NULL
material pointers should not be allowed for the 'tracking' geometry.
A fix has been introduced in G4Region and is included in the development tag
"geommng-V07-00-01". It will be included in future releases.
Thanks.