= checkPrec op (unLoc p1) False `thenM_`
checkPrec op (unLoc p2) True
- check _ = panic "checkPrecMatch"
+ check _ = return ()
+ -- This can happen. Consider
+ -- a `op` True = ...
+ -- op = ...
+ -- The infix flag comes from the first binding of the group
+ -- but the second eqn has no args (an error, but not discovered
+ -- until the type checker). So we don't want to crash on the
+ -- second eqn.
checkPrec op (ConPatIn op1 (InfixCon _ _)) right
= lookupFixityRn op `thenM` \ op_fix@(Fixity op_prec op_dir) ->