2007-01-07  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>

	PR c++/28986
cp/
	* typeck.c (build_binary_op): Call overflow_warning if
	TREE_OVERFLOW_P is true for the result and not for any of the
	operands.

testsuite/
	* g++.dg/conversion/nullptr1.C: Added overflow warning.
	* g++.dg/warn/overflow-warn-1.C: New.
	* g++.dg/warn/overflow-warn-3.C: New.
	* g++.dg/warn/overflow-warn-4.C: New.
	* g++.dg/warn/overflow-warn-5.C: New.
	* g++.dg/warn/overflow-warn-6.C: New.
	* g++.dg/warn/Woverflow-1.C: New.
	* g++.dg/warn/Woverflow-2.C: New.
	* g++.dg/warn/Woverflow-3.C: New.
	* g++.dg/warn/multiple-overflow-warn-2.C: New.

From-SVN: r120558