Missing NULL check

[Mansour Ahmadi]

A NULL check on mspace is missing here:

libredwg/src/out_dxfb.c

Lines 1869 to 1879 in 785df5f

 Dwg_Object *mspace = dwg->header_vars.BLOCK_RECORD_MSPACE->obj; 
  
 SECTION (ENTITIES); 
 for (i = 0; (BITCODE_BL)i < dwg->num_objects; i++) 
   { 
     Dwg_Object *obj = &dwg->object[i]; 
     if (obj->supertype == DWG_SUPERTYPE_ENTITY && obj->type != DWG_TYPE_BLOCK 
         && obj->type != DWG_TYPE_ENDBLK) 
       { 
         Dwg_Object_Ref *owner = obj->tio.entity->ownerhandle; 
         if (!owner || (owner && owner->obj == mspace)) 

While it is done here, which is a similar case:

libredwg/src/out_dxf.c

Lines 2261 to 2274 in 785df5f

 Dwg_Object *mspace = dwg_model_space_object (dwg); 
  
 if (!mspace) 
   return DWG_ERR_INVALIDDWG; 
  
 SECTION (ENTITIES); 
 for (i = 0; (BITCODE_BL)i < dwg->num_objects; i++) 
   { 
     Dwg_Object *obj = &dwg->object[i]; 
     if (obj->supertype == DWG_SUPERTYPE_ENTITY && obj->type != DWG_TYPE_BLOCK 
         && obj->type != DWG_TYPE_ENDBLK) 
       { 
         Dwg_Object_Ref *owner = obj->tio.entity->ownerhandle; 
         if (!owner || (owner && owner->obj == mspace)) 

dwg_model_space_object might return dwg->header_vars.BLOCK_RECORD_MSPACE->obj so I think the semantic is the same.

libredwg/src/dwg.c

Line 861 in 007ebf4

 return dwg->header_vars.BLOCK_RECORD_MSPACE->obj;