Stack trace information extracted with traceback.extract_stack is
incorrect in that the #-*- line causes double counting. For example:

#comment
from traceback import extract_stack
print("this is line", extract_stack()[-1][1])

prints 'this is line 3', but

#comment
#-*- coding: windows-1251 -*-
from traceback import extract_stack
print("this is line", extract_stack()[-1][1])

prints 'this is line 6'

This bug is a duplicate of the issue 2384: I tried your example with 
the patch tokenizer-coding-2.patch and your bug is fixed:
 * first example (no coding): this is line 3
 * second example (with coding): this is line 4