Handle integer overflow in interval justification functions.

justify_interval, justify_hours, and justify_days didn't check for
overflow when promoting hours to days or days to months; but that's
possible when the upper field's value is already large.  Detect and
report any such overflow.

Also, we can avoid unnecessary overflow in some cases in justify_interval
by pre-justifying the days field.  (Thanks to Nathan Bossart for this
idea.)

Joe Koshakow

Discussion: https://postgr.es/m/CAAvxfHeNqsJ2xYFbPUf_8nNQUiJqkag04NW6aBQQ0dbZsxfWHA@mail.gmail.com

2 files changed, 48 insertions, 0 deletions

diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index accd4a7d908..146f7c55d0b 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -396,6 +396,10 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
  @ 7 mons 6 days 5 hours 4 mins 3 secs
 (1 row)
 
+SELECT justify_hours(interval '2147483647 days 24 hrs');
+ERROR:  interval out of range
+SELECT justify_days(interval '2147483647 months 30 days');
+ERROR:  interval out of range
 -- test justify_interval()
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
   1 month -1 hour   
@@ -403,6 +407,38 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
  @ 29 days 23 hours
 (1 row)
 
+SELECT justify_interval(interval '2147483647 days 24 hrs');
+       justify_interval        
+-------------------------------
+ @ 5965232 years 4 mons 8 days
+(1 row)
+
+SELECT justify_interval(interval '-2147483648 days -24 hrs');
+         justify_interval          
+-----------------------------------
+ @ 5965232 years 4 mons 9 days ago
+(1 row)
+
+SELECT justify_interval(interval '2147483647 months 30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '-2147483648 months -30 days');
+ERROR:  interval out of range
+SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+         justify_interval         
+----------------------------------
+ @ 178956970 years 7 mons 29 days
+(1 row)
+
+SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+           justify_interval           
+--------------------------------------
+ @ 178956970 years 8 mons 29 days ago
+(1 row)
+
+SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+ERROR:  interval out of range
+SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+ERROR:  interval out of range
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
 SET IntervalStyle TO postgres;
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 6d532398bd6..c31f0eec054 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -149,10 +149,22 @@ select '100000000y 10mon -1000000000d -100000h -10min -10.000001s ago'::interval
 SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as "6 mons 5 days 4 hours 3 mins 2 seconds";
 SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
 
+SELECT justify_hours(interval '2147483647 days 24 hrs');
+SELECT justify_days(interval '2147483647 months 30 days');
+
 -- test justify_interval()
 
 SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
+SELECT justify_interval(interval '2147483647 days 24 hrs');
+SELECT justify_interval(interval '-2147483648 days -24 hrs');
+SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
 SET IntervalStyle TO postgres;