Null pointer dereference during rule compilation

[dkasak]

Problematic input:

shape N{L(=)[]}
shape L(e)

Valgrind report:

==10794== Memcheck, a memory error detector
==10794== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==10794== Using Valgrind-3.14.0.GIT and LibVEX; rerun with -h for copyright info
==10794== Command: cfdg-github 2
==10794== 
==10794== Invalid read of size 8
==10794==    at 0x14A9E7: std::vector<AST::ASTparameter, std::allocator<AST::ASTparameter> >::begin() const (stl_vector.h:708)
==10794==    by 0x1BE213: AST::ASTruleSpecifier::compile(AST::CompilePhase, Builder*) (astexpression.cpp:2658)
==10794==    by 0x1E7FC0: AST::ASTreplacement::compile(AST::CompilePhase, Builder*) (astreplacement.cpp:638)
==10794==    by 0x1E4012: AST::ASTrepContainer::compile(AST::CompilePhase, Builder*, AST::ASTloop*, AST::ASTdefine*) (astreplacement.cpp:111)
==10794==    by 0x1E9BFA: AST::ASTrule::compile(AST::CompilePhase, Builder*) (astreplacement.cpp:974)
==10794==    by 0x1E4012: AST::ASTrepContainer::compile(AST::CompilePhase, Builder*, AST::ASTloop*, AST::ASTdefine*) (astreplacement.cpp:111)
==10794==    by 0x143FEA: CFDGImpl::rulesLoaded() (cfdgimpl.cpp:459)
==10794==    by 0x134EF1: CFDG::ParseFile(char const*, AbstractSystem*, int) (cfdg.cpp:279)
==10794==    by 0x21CDCA: main (main.cpp:454)
==10794==  Address 0x0 is not stack'd, malloc'd or (recently) free'd
==10794== 
==10794== 
==10794== Process terminating with default action of signal 11 (SIGSEGV)
==10794==  Access not within mapped region at address 0x0
==10794==    at 0x14A9E7: std::vector<AST::ASTparameter, std::allocator<AST::ASTparameter> >::begin() const (stl_vector.h:708)
==10794==    by 0x1BE213: AST::ASTruleSpecifier::compile(AST::CompilePhase, Builder*) (astexpression.cpp:2658)
==10794==    by 0x1E7FC0: AST::ASTreplacement::compile(AST::CompilePhase, Builder*) (astreplacement.cpp:638)
==10794==    by 0x1E4012: AST::ASTrepContainer::compile(AST::CompilePhase, Builder*, AST::ASTloop*, AST::ASTdefine*) (astreplacement.cpp:111)
==10794==    by 0x1E9BFA: AST::ASTrule::compile(AST::CompilePhase, Builder*) (astreplacement.cpp:974)
==10794==    by 0x1E4012: AST::ASTrepContainer::compile(AST::CompilePhase, Builder*, AST::ASTloop*, AST::ASTdefine*) (astreplacement.cpp:111)
==10794==    by 0x143FEA: CFDGImpl::rulesLoaded() (cfdgimpl.cpp:459)
==10794==    by 0x134EF1: CFDG::ParseFile(char const*, AbstractSystem*, int) (cfdg.cpp:279)
==10794==    by 0x21CDCA: main (main.cpp:454)
==10794==  If you believe this happened as a result of a stack
==10794==  overflow in your program's main thread (unlikely but
==10794==  possible), you can try to increase the size of the
==10794==  main thread stack using the --main-stacksize= flag.
==10794==  The main thread stack size used in this run was 8388608.
==10794== 
==10794== HEAP SUMMARY:
==10794==     in use at exit: 67,530 bytes in 240 blocks
==10794==   total heap usage: 594 allocs, 354 frees, 236,041 bytes allocated
==10794== 
==10794== LEAK SUMMARY:
==10794==    definitely lost: 0 bytes in 0 blocks
==10794==    indirectly lost: 0 bytes in 0 blocks
==10794==      possibly lost: 0 bytes in 0 blocks
==10794==    still reachable: 67,530 bytes in 240 blocks
==10794==         suppressed: 0 bytes in 0 blocks
==10794== Rerun with --leak-check=full to see details of leaked memory
==10794== 
==10794== For counts of detected and suppressed errors, rerun with: -v
==10794== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

[MtnViewJohn]

Fixed in version 3.1