[Gmsh] Segfault on bad input file

[D Haley]

Hello,

Just  a quick bug report.

The following file (probably invalid, I was writing it by hand) causes a segfault in gmsh.

gmsh --version
2.4.2
-- FILE CONTENTS--
$MeshFormat                                   
2 0 8                                                                                                  
$EndMeshFormat                                                                                         
$Nodes                                                                                                 
4                                                                                                      
1 0 0 0                                                                                                
2 1 -0 0                                                                                               
3 1 1 0                                                                                                
4 -0 1 0                                                                                               
$EndNodes                                                                                              
$Elements                                                                                              
2                                                                                                      
1 2 3 0 6 0 0 1  2                                                                                     
2 2 3 0 6 0 2 3  4                                                                                     
$EndElements     
------------------------------


Program received signal SIGSEGV, Segmentation fault.
0x000000000058ca20 in _associateEntityWithElementVertices<MTriangle> (
    this=0xd74fb0) at /home/user/source/gmsh-2.4.2-source/Geo/GModel.cpp:757
757	      if (!elements[i]->getVertex(j)->onWhat() ||
(gdb) bt
#0  0x000000000058ca20 in _associateEntityWithElementVertices<MTriangle> (
    this=0xd74fb0) at /home/user/source/gmsh-2.4.2-source/Geo/GModel.cpp:757
#1  GModel::_associateEntityWithMeshVertices (this=0xd74fb0)
    at /home/user/source/gmsh-2.4.2-source/Geo/GModel.cpp:779
#2  0x00000000005ae2e7 in GModel::readMSH (this=<value optimized out>, 
    name=<value optimized out>)
    at /home/user/source/gmsh-2.4.2-source/Geo/GModelIO_Mesh.cpp:461
#3  0x000000000051c142 in MergeFile (fileName=DWARF-2 expression error: DW_OP_reg operations must be used either alone or in conjuction with DW_OP_piece.
)
    at /home/user/source/gmsh-2.4.2-source/Common/OpenFile.cpp:348
#4  0x000000000051c49e in OpenProject (fileName=DWARF-2 expression error: DW_OP_reg operations must be used either alone or in conjuction with DW_OP_piece.
)
    at /home/user/source/gmsh-2.4.2-source/Common/OpenFile.cpp:440
#5  0x00000000004e21c3 in main (argc=<value optimized out>, 
    argv=0x7fffffffdc88)
    at /home/user/source/gmsh-2.4.2-source/Fltk/Main.cpp:76