3 files changed, 57 insertions, 1 deletions
diff --git a/src/test/regress/expected/arrays.out b/src/test/regress/expected/arrays.out
index 6dce5c9301b..4286691f922 100644
--- a/src/test/regress/expected/arrays.out
+++ b/src/test/regress/expected/arrays.out
@@ -1676,3 +1676,33 @@ select * from t1;
  [5:5]={"(42,43)"}
 (1 row)
 
+-- Check that arrays of composites are safely detoasted when needed
+create temp table src (f1 text);
+insert into src
+  select string_agg(random()::text,'') from generate_series(1,10000);
+create type textandtext as (c1 text, c2 text);
+create temp table dest (f1 textandtext[]);
+insert into dest select array[row(f1,f1)::textandtext] from src;
+select length(md5((f1[1]).c2)) from dest;
+ length 
+--------
+     32
+(1 row)
+
+delete from src;
+select length(md5((f1[1]).c2)) from dest;
+ length 
+--------
+     32
+(1 row)
+
+truncate table src;
+drop table src;
+select length(md5((f1[1]).c2)) from dest;
+ length 
+--------
+     32
+(1 row)
+
+drop table dest;
+drop type textandtext;
diff --git a/src/test/regress/regress.c b/src/test/regress/regress.c
index c25bf6e09d1..4b69067485d 100644
--- a/src/test/regress/regress.c
+++ b/src/test/regress/regress.c
@@ -810,5 +810,14 @@ make_tuple_indirect(PG_FUNCTION_ARGS)
 
 	MemoryContextSwitchTo(old_context);
 
-	PG_RETURN_HEAPTUPLEHEADER(newtup->t_data);
+	/*
+	 * We intentionally don't use PG_RETURN_HEAPTUPLEHEADER here, because that
+	 * would cause the indirect toast pointers to be flattened out of the
+	 * tuple immediately, rendering subsequent testing irrelevant.  So just
+	 * return the HeapTupleHeader pointer as-is.  This violates the general
+	 * rule that composite Datums shouldn't contain toast pointers, but so
+	 * long as the regression test scripts don't insert the result of this
+	 * function into a container type (record, array, etc) it should be OK.
+	 */
+	PG_RETURN_POINTER(newtup->t_data);
 }
diff --git a/src/test/regress/sql/arrays.sql b/src/test/regress/sql/arrays.sql
index 92af172dfc4..d9f7cbfa8d2 100644
--- a/src/test/regress/sql/arrays.sql
+++ b/src/test/regress/sql/arrays.sql
@@ -459,3 +459,20 @@ insert into t1 (f1[5].q1) values(42);
 select * from t1;
 update t1 set f1[5].q2 = 43;
 select * from t1;
+
+-- Check that arrays of composites are safely detoasted when needed
+
+create temp table src (f1 text);
+insert into src
+  select string_agg(random()::text,'') from generate_series(1,10000);
+create type textandtext as (c1 text, c2 text);
+create temp table dest (f1 textandtext[]);
+insert into dest select array[row(f1,f1)::textandtext] from src;
+select length(md5((f1[1]).c2)) from dest;
+delete from src;
+select length(md5((f1[1]).c2)) from dest;
+truncate table src;
+drop table src;
+select length(md5((f1[1]).c2)) from dest;
+drop table dest;
+drop type textandtext;