Message 188477 - Python tracker

I didn't add the following optimization (proposed by Serhiy in his review) because I'm not convinced that it's faster, and it's unrelated to this issue:

   if (width > (PY_SSIZE_T_MAX - 9) / 10
       && width > (PY_SSIZE_T_MAX - ((int)*f - '0')) / 10)
   { ... }

instead of 

   if (width > (PY_SSIZE_T_MAX - ((int)*f - '0')) / 10)
   { ... }