Can benzaldehyde undergo chlorination (aka halogenation)?
The experimental process of chlorination of benzaldehyde to form benzoyl chloride can be found here:


  
  
  A round bottom flask is fitted with a reflux condenser and a gas inlet
  tube. 100 grams of cold and dry benzaldehyde are added to the flask
  and saturated with the current of dry chlorine. The chlorine gas is
  readily absorbed and the evolution hydrogen chloride takes place. When
  the reaction has moderated, the external heat is applied by
  keeping gentle boiling. The stream of chlorine is continued until no
  more hydrogen chloride is evolved. A stream of dry air or carbon
  dioxide is then passed through the apparatus in order to remove
  an excess of chlorine. Benzoyl chloride is obtained by distillation as
  a colorless fuming liquid with a very irritating smell. Yield almost
  quantitative.
  
  Preparation of organic compounds, E. de. Barry Barnett, 52, 1912


There is also a German paper written by Freidrich Wohler and Justus von Leibig which mentions an early preparation of benzoyl chloride by the action of chlorine over benzaldehyde.