- // Windows-specific code to set the horizontal extent of the listbox, if
- // necessary. If s is non-NULL, it's used to calculate the horizontal
- // extent. Otherwise, all strings are used.
+ // Windows-specific code to update the horizontal extent of the listbox, if
+ // necessary. If s is non-empty, the horizontal extent is increased to the
+ // length of this string if it's currently too short, otherwise the maximum
+ // extent of all strings is used. In any case calls InvalidateBestSize()