PyLong_FromString(): fix Coverity CID 1424951 (#4738)

Explicitly cast digits (Py_ssize_t) to double to fix the following
false-alarm warning from Coverity:

"fsize_z = digits * log_base_BASE[base] + 1;"

CID 1424951: Incorrect expression (UNINTENDED_INTEGER_DIVISION)
Dividing integer expressions "9223372036854775783UL" and "4UL", and
then converting the integer quotient to type "double". Any remainder,
or fractional part of the quotient, is ignored.
This commit is contained in:
Victor Stinner 2017-12-08 00:06:55 +01:00 committed by GitHub
parent a0374dd34a
commit dd431b32f4
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@ -2267,7 +2267,6 @@ just 1 digit at the start, so that the copying code was exercised for every
digit beyond the first.
***/
twodigits c; /* current input character */
double fsize_z;
Py_ssize_t size_z;
Py_ssize_t digits = 0;
int i;
@ -2331,8 +2330,8 @@ digit beyond the first.
* need to initialize z->ob_digit -- no slot is read up before
* being stored into.
*/
fsize_z = digits * log_base_BASE[base] + 1;
if (fsize_z > MAX_LONG_DIGITS) {
double fsize_z = (double)digits * log_base_BASE[base] + 1.0;
if (fsize_z > (double)MAX_LONG_DIGITS) {
/* The same exception as in _PyLong_New(). */
PyErr_SetString(PyExc_OverflowError,
"too many digits in integer");