Mercurial > cpython-lru_cache-weakref
diff Python/compile.c @ 42704:092f02cf018f legacy-trunk
Fix compile.c so that it records 0.0 and -0.0 as separate constants in a code
object's co_consts tuple; add a test to show that the previous behavior (where
these two constants were "collapsed" into one) causes serious malfunctioning.
| author | Alex Martelli <aleaxit@gmail.com> |
|---|---|
| date | Wed, 22 Aug 2007 21:14:17 +0000 |
| parents | 90487a887be1 |
| children | 1b420e6e00eb |
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--- a/Python/compile.c Wed Aug 22 19:05:21 2007 +0000 +++ b/Python/compile.c Wed Aug 22 21:14:17 2007 +0000 @@ -907,7 +907,20 @@ Py_ssize_t arg; /* necessary to make sure types aren't coerced (e.g., int and long) */ - t = PyTuple_Pack(2, o, o->ob_type); + /* _and_ to distinguish 0.0 from -0.0 e.g. on IEEE platforms */ + if (PyFloat_Check(o)) { + double d = PyFloat_AS_DOUBLE(o); + unsigned char* p = (unsigned char*) &d; + /* all we need is to make the tuple different in either the 0.0 + * or -0.0 case from all others, just to avoid the "coercion". + */ + if (*p==0 && p[sizeof(double)-1]==0) + t = PyTuple_Pack(3, o, o->ob_type, Py_None); + else + t = PyTuple_Pack(2, o, o->ob_type); + } else { + t = PyTuple_Pack(2, o, o->ob_type); + } if (t == NULL) return -1;