SALEM, Ore. — A Salem taxi company is offering homeless people a seat inside its cabs on chilly nights when the city’s warming centers are not open. Willamette Valley Yellow Cab usually offers free rides to shelters on cold nights, but this winter, they are going further because of a controversy over when the city’s warming shelters will open, the Statesman Journal reported Friday. The Mid-Valley Community Action Agency, the nonprofit in charge of opening the warming centers, doesn’t do so unless the overnight temperature is forecast to dip to 27 degrees or below for three nights in a row.