Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit4f4a001

Browse files
committed
Fix corner-case 64-bit integer subtraction bug on some platforms.
When computing "0 - INT64_MIN", most platforms would report anoverflow error, which is correct. However, platforms without integeroverflow builtins or 128-bit integers would fail to spot the overflow,and incorrectly return INT64_MIN.Back-patch to all supported branches.Patch be me. Thanks to Jian He for initial investigation, and LaurenzAlbe and Tom Lane for review.Discussion:https://postgr.es/m/CAEZATCUNK-AZSD0jVdgkk0N%3DNcAXBWeAEX-QU9AnJPensikmdQ%40mail.gmail.com
1 parent319310a commit4f4a001

File tree

3 files changed

+8
-1
lines changed

3 files changed

+8
-1
lines changed

‎src/include/common/int.h

Lines changed: 5 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -200,8 +200,12 @@ pg_sub_s64_overflow(int64 a, int64 b, int64 *result)
200200
*result= (int64)res;
201201
return false;
202202
#else
203+
/*
204+
* Note: overflow is also possible when a == 0 and b < 0 (specifically,
205+
* when b == PG_INT64_MIN).
206+
*/
203207
if ((a<0&&b>0&&a<PG_INT64_MIN+b)||
204-
(a>0&&b<0&&a>PG_INT64_MAX+b))
208+
(a >=0&&b<0&&a>PG_INT64_MAX+b))
205209
{
206210
*result=0x5EED;/* to avoid spurious warnings */
207211
return true;

‎src/test/regress/expected/int8.out

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -659,6 +659,8 @@ select -('-9223372036854775807'::int8);
659659

660660
select -('-9223372036854775808'::int8);
661661
ERROR: bigint out of range
662+
select 0::int8 - '-9223372036854775808'::int8;
663+
ERROR: bigint out of range
662664
select '9223372036854775800'::int8 + '9223372036854775800'::int8;
663665
ERROR: bigint out of range
664666
select '-9223372036854775800'::int8 + '-9223372036854775800'::int8;

‎src/test/regress/sql/int8.sql

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -131,6 +131,7 @@ select '9223372036854775808'::int8;
131131

132132
select-('-9223372036854775807'::int8);
133133
select-('-9223372036854775808'::int8);
134+
select0::int8-'-9223372036854775808'::int8;
134135

135136
select'9223372036854775800'::int8+'9223372036854775800'::int8;
136137
select'-9223372036854775800'::int8+'-9223372036854775800'::int8;

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp