re PR c++/51326 (ICE with invalid override)

/cp
2011-12-01  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/51326
	* call.c (build_user_type_conversion_1): Early return NULL if
	expr is NULL_TREE.

/testsuite
2011-12-01  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/51326
	* g++.dg/inherit/crash3.C: New.

From-SVN: r181895