/cp
2017-12-13  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/81061
	* typeck.c (cp_build_modify_expr): Upon cxx_readonly_error
	immediately return error_mark_node.

/testsuite
2017-12-13  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/81061
	* g++.dg/other/const5.C: New.

From-SVN: r255613