Using master. During startup, if you open `Window` -> `Console` and try and execute any command (can be garbage) `bitcoin-qt` will crash:
```bash
On branch pull/16118/local-merge

Process 89287 launched: '/Users/michael/github/bitcoin/src/qt/bitcoin-qt' (x86_64)
2019-05-29 09:57:56.276746-0400 bitcoin-qt[89287:939924] MessageTracer: Falling back to default whitelist
Process 89287 stopped
* thread #1, name = 'bitcoin-main', queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x8)
    frame #0: 0x00000001015158ba QtWidgets`QCompleter::popup() const + 10
QtWidgets`QCompleter::popup:
->  0x1015158ba <+10>: movq   0x8(%rdi), %rbx
    0x1015158be <+14>: movq   0x88(%rbx), %rax
    0x1015158c5 <+21>: testq  %rax, %rax
    0x1015158c8 <+24>: jne    0x101515942               ; <+146>
Target 0: (bitcoin-qt) stopped.
```

Not sure if just disabling the menu, like in #16118 would be ok, as a user might actually want to be able to run a command.
case STATE_DOUBLEQUOTED: 
                switch(ch)
            {
                case '"': state = STATE_ARGUMENT; break;
                case '\\': state = STATE_ESCAPE_DOUBLEQUOTED; break;
                default: curarg += ch;
            }
                break;
            case STATE_ESCAPE_OUTER: 
                curarg += ch; state = STATE_ARGUMENT;
                break;
            case STATE_ESCAPE_DOUBLEQUOTED: 
                if(ch != '"' && ch != '\\') curarg += '\\'; 
                curarg += ch; state = STATE_DOUBLEQUOTED;
                break;
        }
    }
    if (pstrFilteredOut) {
        if (STATE_COMMAND_EXECUTED == state) {
            assert(!stack.empty());
            close_out_params();
        }
        *pstrFilteredOut = strCommand;
        for (auto i = filter_ranges.rbegin(); i != filter_ranges.rend(); ++i) {
            pstrFilteredOut->replace(i->first, i->second - i->first, "(…)");
        }
    }
    switch(state) // 
    {
        case STATE_COMMAND_EXECUTED: