Coventry City remain in thirteenth place in the League One table after their 0-0 draw with Bradford City.
Wolves stay six points clear at the top after a 0-0 draw at Stevenage, who move off the bottom of the table and go above Shrewsbury Town. The side from Molineux lead the table from Brentford who drew 0-0 at Sheffield United.
In the only League One game that had any goals, Micky Adams' Port Vale side beat Crawley Town 2-1.