Allow to_timestamp(float8) to convert float infinity to timestamp infinity.

With the original SQL-function implementation, such cases failed because
we don't support infinite intervals.  Converting the function to C lets
us bypass the interval representation, which should be a bit faster as
well as more flexible.

Vitaly Burovoy, reviewed by Anastasia Lubennikova

2 files changed, 62 insertions, 0 deletions

diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index 271873d326..9627aa3671 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2307,6 +2307,53 @@ SELECT make_timestamptz(2007, 12, 9, 3, 0, 0, 'VET');
  Sun Dec 09 07:30:00 2007 UTC
 (1 row)
 
+SELECT to_timestamp(         0);          -- 1970-01-01 00:00:00+00
+         to_timestamp         
+------------------------------
+ Thu Jan 01 00:00:00 1970 UTC
+(1 row)
+
+SELECT to_timestamp( 946684800);          -- 2000-01-01 00:00:00+00
+         to_timestamp         
+------------------------------
+ Sat Jan 01 00:00:00 2000 UTC
+(1 row)
+
+SELECT to_timestamp(1262349296.7890123);  -- 2010-01-01 12:34:56.789012+00
+            to_timestamp             
+-------------------------------------
+ Fri Jan 01 12:34:56.789012 2010 UTC
+(1 row)
+
+-- edge cases
+SELECT to_timestamp(-1e20::float8);       -- error, out of range
+ERROR:  timestamp out of range: "-1e+20"
+SELECT to_timestamp(-210866803200.0625);  -- error, out of range
+ERROR:  timestamp out of range: "-2.10867e+11"
+SELECT to_timestamp(-210866803200);       --   4714-11-24 00:00:00+00 BC
+          to_timestamp           
+---------------------------------
+ Mon Nov 24 00:00:00 4714 UTC BC
+(1 row)
+
+-- The upper boundary differs between integer and float timestamps, so check the biggest one
+SELECT to_timestamp(185331707078400::float8);  -- error, out of range
+ERROR:  timestamp out of range: "1.85332e+14"
+-- nonfinite values
+SELECT to_timestamp(' Infinity'::float);
+ to_timestamp 
+--------------
+ infinity
+(1 row)
+
+SELECT to_timestamp('-Infinity'::float);
+ to_timestamp 
+--------------
+ -infinity
+(1 row)
+
+SELECT to_timestamp('NaN'::float);
+ERROR:  timestamp cannot be NaN
 SET TimeZone to 'Europe/Moscow';
 SELECT '2011-03-26 21:00:00 UTC'::timestamptz;
          timestamptz          
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 5ec92e55c8..35470ce7c9 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -403,6 +403,21 @@ SELECT '2007-12-09 04:00:00'::timestamp AT TIME ZONE 'VET';
 SELECT make_timestamptz(2007, 12, 9, 2, 0, 0, 'VET');
 SELECT make_timestamptz(2007, 12, 9, 3, 0, 0, 'VET');
 
+SELECT to_timestamp(         0);          -- 1970-01-01 00:00:00+00
+SELECT to_timestamp( 946684800);          -- 2000-01-01 00:00:00+00
+SELECT to_timestamp(1262349296.7890123);  -- 2010-01-01 12:34:56.789012+00
+-- edge cases
+SELECT to_timestamp(-1e20::float8);       -- error, out of range
+SELECT to_timestamp(-210866803200.0625);  -- error, out of range
+SELECT to_timestamp(-210866803200);       --   4714-11-24 00:00:00+00 BC
+-- The upper boundary differs between integer and float timestamps, so check the biggest one
+SELECT to_timestamp(185331707078400::float8);  -- error, out of range
+-- nonfinite values
+SELECT to_timestamp(' Infinity'::float);
+SELECT to_timestamp('-Infinity'::float);
+SELECT to_timestamp('NaN'::float);
+
+
 SET TimeZone to 'Europe/Moscow';
 
 SELECT '2011-03-26 21:00:00 UTC'::timestamptz;