Respect the strip_results parameter in unsafe_format. No one uses it so there isn't any rush to incorporate this push.

src/calibre/utils/formatter.py

@@ -506,7 +506,7 @@ def unsafe_format(self, fmt, kwargs, book, strip_results=True):
         self.book = book
         self.composite_values = {}
         self.locals = {}
-        return self.evaluate(fmt, [], kwargs).strip()
+        return self.evaluate(fmt, [], kwargs)
 
     ########## a formatter guaranteed not to throw an exception ############