@amaury: Oops, yes, I introduced a refleak in the version 4 with the 
PyUnicode_Check(). Instead of just moved Py_(X)RECREF(lineobj);, I 
could not not resist to refactor the code to remove one more 
indentation level (I prefer if (...) return; instead of if (...) { 
very long block; }).

Changes in version 5:
 - rename 'namebuf' buffer to 'buf', it's used for the filename and to 
display the indentation space (strcpy(buf, '          ');).
 - move Py_DECREF(fob); at the end of the GetLine loop
 - return on lineobj error

I think that the new version is easier to read than the current code 
because they are few indentation and no more local variables (if (...) 
{ local var; ... })