BUG: in 'computesizes', 'twotoi' overflows when a sequence has

more than 2^30 elements.
This commit is contained in:
Roberto Ierusalimschy 2017-05-19 09:57:10 -03:00
parent e39ee2cc58
commit e3d52da144

View File

@ -1,5 +1,5 @@
/*
** $Id: ltable.c,v 2.120 2017/05/16 19:07:08 roberto Exp roberto $
** $Id: ltable.c,v 2.121 2017/05/19 12:47:00 roberto Exp roberto $
** Lua tables (hash)
** See Copyright Notice in lua.h
*/
@ -214,7 +214,8 @@ int luaH_next (lua_State *L, Table *t, StkId key) {
** "count array" where 'nums[i]' is the number of integers in the table
** between 2^(i - 1) + 1 and 2^i. 'pna' enters with the total number of
** integer keys in the table and leaves with the number of keys that
** will go to the array part; return the optimal size.
** will go to the array part; return the optimal size. (The condition
** 'twotoi > 0' in the for loop stops the loop if 'twotoi' overflows.)
*/
static unsigned int computesizes (unsigned int nums[], unsigned int *pna) {
int i;
@ -223,7 +224,9 @@ static unsigned int computesizes (unsigned int nums[], unsigned int *pna) {
unsigned int na = 0; /* number of elements to go to array part */
unsigned int optimal = 0; /* optimal size for array part */
/* loop while keys can fill more than half of total size */
for (i = 0, twotoi = 1; *pna > twotoi / 2; i++, twotoi *= 2) {
for (i = 0, twotoi = 1;
twotoi > 0 && *pna > twotoi / 2;
i++, twotoi *= 2) {
a += nums[i];
if (a > twotoi/2) { /* more than half elements present? */
optimal = twotoi; /* optimal size (till now) */