PR c/15444
	* c-format.c (avoid_dollar_number): New function.
	(check_format_info_main): Call avoid_dollar_number when operand
	numbers might occur but has_operand_number == 0.

testsuite:
	* gcc.dg/format/xopen-1.c: Adjust expected message.
	* gcc.dg/format/xopen-3.c: New test.

From-SVN: r81871