postgres
diff --git a/‎src/backend/access/common/heaptuple.c
Lines changed: 1 addition & 1 deletion b/‎src/backend/access/common/heaptuple.c
Lines changed: 1 addition & 1 deletion
diff --git a/‎src/backend/commands/trigger.c
Lines changed: 1 addition & 4 deletions b/‎src/backend/commands/trigger.c
Lines changed: 1 addition & 4 deletions
diff --git a/‎src/include/access/htup_details.h
Lines changed: 3 additions & 4 deletions b/‎src/include/access/htup_details.h
Lines changed: 3 additions & 4 deletions
diff --git a/‎src/test/regress/expected/fast_default.out
Lines changed: 27 additions & 0 deletions b/‎src/test/regress/expected/fast_default.out
Lines changed: 27 additions & 0 deletions
diff --git a/‎src/test/regress/sql/fast_default.sql
Lines changed: 20 additions & 0 deletions b/‎src/test/regress/sql/fast_default.sql
Lines changed: 20 additions & 0 deletions
@@ -80,7 +80,7 @@
 /*
  * Return the missing value of an attribute, or NULL if there isn't one.
  */
-static Datum
+Datum
 getmissingattr(TupleDesc tupleDesc,
 			   int attnum, bool *isnull)
 {
 
@@ -3396,10 +3396,7 @@ ltrmark:;
 		LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
 	}
 
-	if (HeapTupleHeaderGetNatts(tuple.t_data) < relation->rd_att->natts)
-		result = heap_expand_tuple(&tuple, relation->rd_att);
-	else
-		result = heap_copytuple(&tuple);
+	result = heap_copytuple(&tuple);
 	ReleaseBuffer(buffer);
 
 	return result;
 
@@ -783,10 +783,7 @@ extern Datum fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
 		((attnum) > 0) ? \
 		( \
 			((attnum) > (int) HeapTupleHeaderGetNatts((tup)->t_data)) ? \
-			( \
-				(*(isnull) = true), \
-				(Datum)NULL \
-			) \
+				getmissingattr((tupleDesc), (attnum), (isnull)) \
 			: \
 				fastgetattr((tup), (attnum), (tupleDesc), (isnull)) \
 		) \
@@ -807,6 +804,8 @@ extern Datum nocachegetattr(HeapTuple tup, int attnum,
 			   TupleDesc att);
 extern Datum heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
 				bool *isnull);
+extern Datum getmissingattr(TupleDesc tupleDesc,
+			   int attnum, bool *isnull);
 extern HeapTuple heap_copytuple(HeapTuple tuple);
 extern void heap_copytuple_with_tuple(HeapTuple src, HeapTuple dest);
 extern Datum heap_copy_tuple_as_datum(HeapTuple tuple, TupleDesc tupleDesc);
 
@@ -770,6 +770,33 @@ SELECT * FROM vtype2;
  2 | yyy
 (2 rows)
 
+-- Ensure that defaults are checked when evaluating whether HOT update
+-- is possible, this was broken for a while:
+-- https://postgr.es/m/20190202133521.ylauh3ckqa7colzj%40alap3.anarazel.de
+BEGIN;
+CREATE TABLE t();
+INSERT INTO t DEFAULT VALUES;
+ALTER TABLE t ADD COLUMN a int DEFAULT 1;
+CREATE INDEX ON t(a);
+-- set column with a default 1 to NULL, due to a bug that wasn't
+-- noticed has heap_getattr buggily returned NULL for default columns
+UPDATE t SET a = NULL;
+-- verify that index and non-index scans show the same result
+SET LOCAL enable_seqscan = true;
+SELECT * FROM t WHERE a IS NULL;
+ a 
+---
+  
+(1 row)
+
+SET LOCAL enable_seqscan = false;
+SELECT * FROM t WHERE a IS NULL;
+ a 
+---
+  
+(1 row)
+
+ROLLBACK;
 -- cleanup
 DROP TABLE vtype;
 DROP TABLE vtype2;
 
@@ -505,6 +505,26 @@ ALTER TABLE vtype2 ALTER COLUMN b TYPE varchar(20) USING b::varchar(20);
 SELECT * FROM vtype2;
 
 
+-- Ensure that defaults are checked when evaluating whether HOT update
+-- is possible, this was broken for a while:
+-- https://postgr.es/m/20190202133521.ylauh3ckqa7colzj%40alap3.anarazel.de
+BEGIN;
+CREATE TABLE t();
+INSERT INTO t DEFAULT VALUES;
+ALTER TABLE t ADD COLUMN a int DEFAULT 1;
+CREATE INDEX ON t(a);
+-- set column with a default 1 to NULL, due to a bug that wasn't
+-- noticed has heap_getattr buggily returned NULL for default columns
+UPDATE t SET a = NULL;
+
+-- verify that index and non-index scans show the same result
+SET LOCAL enable_seqscan = true;
+SELECT * FROM t WHERE a IS NULL;
+SET LOCAL enable_seqscan = false;
+SELECT * FROM t WHERE a IS NULL;
+ROLLBACK;
+
+
 -- cleanup
 DROP TABLE vtype;
 DROP TABLE vtype2;