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Pick UINT_MAX / 100 as an upperbound.

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The fix that I applied in r286798 is already good, but it assumes that
sizeof(int) > sizeof(short). Express the upperbound in terms of
UINT_MAX. By dividing that by 100, we're sure that the resulting value
is never larger than approximately UINT_MAX / 10, which is safe.

PR:		202326
Discussed with:	kcwu csie org
MFC after:	1 month
This commit is contained in:
Ed Schouten 2015-08-16 13:59:11 +00:00
parent 4b6578dc8c
commit cd69db4b0e
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=286827
1 changed files with 9 additions and 6 deletions
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15
sys/teken/teken.c
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@ -411,13 +411,16 @@ teken_state_numbers(teken_t *t, teken_char_t c)
/* First digit. */
t->t_stateflags &= ~TS_FIRSTDIGIT;
t->t_nums[t->t_curnum] = c - '0';
} else if (t->t_nums[t->t_curnum] < USHRT_MAX) {
} else if (t->t_nums[t->t_curnum] < UINT_MAX / 100) {
/*
* Screen positions are stored as unsigned
* shorts. There is no need to continue parsing
* input once the value exceeds USHRT_MAX. It
* would only allow for integer overflows when
* performing arithmetic on the cursor position.
* There is no need to continue parsing input
* once the value exceeds the size of the
* terminal. It would only allow for integer
* overflows when performing arithmetic on the
* cursor position.
*
* Ignore any further digits if the value is
* already UINT_MAX / 100.
*/
t->t_nums[t->t_curnum] =
t->t_nums[t->t_curnum] * 10 + c - '0';