Fix issue 20133: do not crash if debug port is illegal.

runtime/bin/dbg_connection.cc

Index: runtime/bin/dbg_connection.cc
===================================================================
--- runtime/bin/dbg_connection.cc	(revision 41134)
+++ runtime/bin/dbg_connection.cc	(working copy)
@@ -331,6 +331,12 @@
   listener_fd_ = ServerSocket::CreateBindListen(
       addresses->GetAt(0)->addr(), port_number, 1);
   delete addresses;
+  if (listener_fd_ < 0) {
+    fprintf(stderr, "%s", "Could not initialize debug socket\n");
+    fflush(stderr);
+    exit(255);

[siva, 2014/10/15 22:58:41]

This file seems to use FATAL("....") whenever it gets an error, see above.

[srdjan, 2014/10/16 15:47:45]

FATAL crashes the VM, I assume it is used for the cases that cannot occur in
normal operation. Since the failure of creating a listener_fd_ can occur when
passing wrong arguments, this CL reports an error without crashing the VM.

+  }
+
   port_number = Socket::GetPort(listener_fd_);
   DebuggerConnectionImpl::StartHandler(port_number);
   return port_number;