[QScintilla] Using python strings with SendScintilla

[Baz Walter]

i am using the following python method to get undecoded strings from 
scintilla:

     def range(self, start, end, decode=True):
         bytes = '\1' * (end - start)
         self.SendScintilla(QSB.SCI_GETTEXTRANGE, start, end, bytes)
         if decode:
             return bytes.decode('utf8')
         return bytes

it works fine, but i noticed some very odd behaviour when i used space 
characters to create the string buffer. what would happen is that string 
literals used elsewhere in my program would become overwritten by 
different characters. so, for instance, my comment method would start 
inserting '#b' at the beginning of a line instead of '# '. my guess 
about the cause of this is that it has something to do with python's 
interning of certain string literals (which includes all the single byte 
strings from 0-255). there seems to be a risk that interned python 
strings could become 'corrupted' when used to create a buffer that is 
passed to SendScintilla.

unfortunately i can't provide example code that demonstrates this 
problem, because it is very unpredictable. all i can say with certainty 
is that if i use a control character to create the buffer, the problem 
goes away. (unless it's '\0', which creates even less predictable 
truncation problems).

obviously, i'm hoping that this is a bug that can be fixed as it took me 
a *long* time to work out what was causing some very weird problems in 
my program. but if not: what would be the safest way to create python 
string buffers for use with SendScintilla - is the above method the best 
i can do? (i think the use of '\1' for the buffer only works because 
it's not being used as a string literal elsewhere in my program).

ps. the reason for bothering with all this is: speed. working with 
undecoded strings is much faster for certain operations (like stripping 
trailing spaces or replacing tabs).