Fix ARRAY_SUBLINK and ARRAY[] for int2vector and oidvector input.

If the given input_type yields valid results from both
get_element_type and get_array_type, initArrayResultAny believed the
former and treated the input as an array type.  However this is
inconsistent with what get_promoted_array_type does, leading to
situations where the output of an ARRAY() subquery is labeled with
the wrong type: it's labeled as oidvector[] but is really a 2-D
array of OID.  That at least results in strange output, and can
result in crashes if further processing such as unnest() is applied.
AFAIK this is only possible with the int2vector and oidvector
types, which are special-cased to be treated mostly as true arrays
even though they aren't quite.

Fix by switching the logic to match get_promoted_array_type by
testing get_array_type not get_element_type, and remove an Assert
thereby made pointless.  (We need not introduce a symmetrical
check for get_element_type in the other if-branch, because
initArrayResultArr will check it.)  This restores the behavior
that existed before bac27394a introduced initArrayResultAny:
the output really is int2vector[] or oidvector[].

Comparable confusion exists when an input of an ARRAY[] construct
is int2vector or oidvector: transformArrayExpr decides it's dealing
with a multidimensional array constructor, and we end up with
something that's a multidimensional OID array but is alleged to be
of type oidvector.  I have not found a crashing case here, but it's
easy to demonstrate totally-wrong results.  Adjust that code so
that what you get is an oidvector[] instead, for consistency with
ARRAY() subqueries.  (This change also makes these types work like
domains-over-arrays in this context, which seems correct.)

Bug: #18840
Reported-by: yang lei <ylshiyu@126.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/18840-fbc9505f066e50d6@postgresql.org
Backpatch-through: 13

diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 3905dd36340e06e653c6b9641792913a8f2b06ea..2258701f3013a038912cb6ab742bc715cce68cab 100644 (file)
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -2055,10 +2055,18 @@ transformArrayExpr(ParseState *pstate, A_ArrayExpr *a,
 
            /*
             * Check for sub-array expressions, if we haven't already found
-            * one.
+            * one.  Note we don't accept domain-over-array as a sub-array,
+            * nor int2vector nor oidvector; those have constraints that don't
+            * map well to being treated as a sub-array.
             */
-           if (!newa->multidims && type_is_array(exprType(newe)))
-               newa->multidims = true;
+           if (!newa->multidims)
+           {
+               Oid         newetype = exprType(newe);
+
+               if (newetype != INT2VECTOROID && newetype != OIDVECTOROID &&
+                   type_is_array(newetype))
+                   newa->multidims = true;
+           }
        }
 
        newelems = lappend(newelems, newe);

diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c
index e5c7e57a5decf8e3e59853e76377796c7bfeb2c6..2fbd1972d7220232b74088501c4b6327722a6f90 100644 (file)
--- a/src/backend/utils/adt/arrayfuncs.c
+++ b/src/backend/utils/adt/arrayfuncs.c
@@ -5770,9 +5770,14 @@ ArrayBuildStateAny *
 initArrayResultAny(Oid input_type, MemoryContext rcontext, bool subcontext)
 {
    ArrayBuildStateAny *astate;
-   Oid         element_type = get_element_type(input_type);
 
-   if (OidIsValid(element_type))
+   /*
+    * int2vector and oidvector will satisfy both get_element_type and
+    * get_array_type.  We prefer to treat them as scalars, to be consistent
+    * with get_promoted_array_type.  Hence, check get_array_type not
+    * get_element_type.
+    */
+   if (!OidIsValid(get_array_type(input_type)))
    {
        /* Array case */
        ArrayBuildStateArr *arraystate;
@@ -5789,9 +5794,6 @@ initArrayResultAny(Oid input_type, MemoryContext rcontext, bool subcontext)
        /* Scalar case */
        ArrayBuildState *scalarstate;
 
-       /* Let's just check that we have a type that can be put into arrays */
-       Assert(OidIsValid(get_array_type(input_type)));
-
        scalarstate = initArrayResult(input_type, rcontext, subcontext);
        astate = (ArrayBuildStateAny *)
            MemoryContextAlloc(scalarstate->mcontext,

diff --git a/src/test/regress/expected/arrays.out b/src/test/regress/expected/arrays.out
index a6d81fd5f9284c9af5e5faa6c280c9f59afadfd5..44fa7b214c71ad46fb65871c205210cd914808d1 100644 (file)
--- a/src/test/regress/expected/arrays.out
+++ b/src/test/regress/expected/arrays.out
@@ -2457,6 +2457,132 @@ select array(select array['Hello', i::text] from generate_series(9,11) i);
  {{Hello,9},{Hello,10},{Hello,11}}
 (1 row)
 
+-- int2vector and oidvector should be treated as scalar types for this purpose
+select pg_typeof(array(select '11 22 33'::int2vector from generate_series(1,5)));
+  pg_typeof   
+--------------
+ int2vector[]
+(1 row)
+
+select array(select '11 22 33'::int2vector from generate_series(1,5));
+                          array                           
+----------------------------------------------------------
+ {"11 22 33","11 22 33","11 22 33","11 22 33","11 22 33"}
+(1 row)
+
+select unnest(array(select '11 22 33'::int2vector from generate_series(1,5)));
+  unnest  
+----------
+ 11 22 33
+ 11 22 33
+ 11 22 33
+ 11 22 33
+ 11 22 33
+(5 rows)
+
+select pg_typeof(array(select '11 22 33'::oidvector from generate_series(1,5)));
+  pg_typeof  
+-------------
+ oidvector[]
+(1 row)
+
+select array(select '11 22 33'::oidvector from generate_series(1,5));
+                          array                           
+----------------------------------------------------------
+ {"11 22 33","11 22 33","11 22 33","11 22 33","11 22 33"}
+(1 row)
+
+select unnest(array(select '11 22 33'::oidvector from generate_series(1,5)));
+  unnest  
+----------
+ 11 22 33
+ 11 22 33
+ 11 22 33
+ 11 22 33
+ 11 22 33
+(5 rows)
+
+-- array[] should do the same
+select pg_typeof(array['11 22 33'::int2vector]);
+  pg_typeof   
+--------------
+ int2vector[]
+(1 row)
+
+select array['11 22 33'::int2vector];
+    array     
+--------------
+ {"11 22 33"}
+(1 row)
+
+select pg_typeof(unnest(array['11 22 33'::int2vector]));
+ pg_typeof  
+------------
+ int2vector
+(1 row)
+
+select unnest(array['11 22 33'::int2vector]);
+  unnest  
+----------
+ 11 22 33
+(1 row)
+
+select pg_typeof(unnest('11 22 33'::int2vector));
+ pg_typeof 
+-----------
+ smallint
+ smallint
+ smallint
+(3 rows)
+
+select unnest('11 22 33'::int2vector);
+ unnest 
+--------
+     11
+     22
+     33
+(3 rows)
+
+select pg_typeof(array['11 22 33'::oidvector]);
+  pg_typeof  
+-------------
+ oidvector[]
+(1 row)
+
+select array['11 22 33'::oidvector];
+    array     
+--------------
+ {"11 22 33"}
+(1 row)
+
+select pg_typeof(unnest(array['11 22 33'::oidvector]));
+ pg_typeof 
+-----------
+ oidvector
+(1 row)
+
+select unnest(array['11 22 33'::oidvector]);
+  unnest  
+----------
+ 11 22 33
+(1 row)
+
+select pg_typeof(unnest('11 22 33'::oidvector));
+ pg_typeof 
+-----------
+ oid
+ oid
+ oid
+(3 rows)
+
+select unnest('11 22 33'::oidvector);
+ unnest 
+--------
+     11
+     22
+     33
+(3 rows)
+
 -- Insert/update on a column that is array of composite
 create temp table t1 (f1 int8_tbl[]);
 insert into t1 (f1[5].q1) values(42);

diff --git a/src/test/regress/sql/arrays.sql b/src/test/regress/sql/arrays.sql
index 47058dfde5092b557c070ae71df0e5aa538e490e..305371debae3b945f9cd17dfd9745c97b2f2bb82 100644 (file)
--- a/src/test/regress/sql/arrays.sql
+++ b/src/test/regress/sql/arrays.sql
@@ -713,6 +713,28 @@ select array_replace(array['AB',NULL,'CDE'],NULL,'12');
 select array(select array[i,i/2] from generate_series(1,5) i);
 select array(select array['Hello', i::text] from generate_series(9,11) i);
 
+-- int2vector and oidvector should be treated as scalar types for this purpose
+select pg_typeof(array(select '11 22 33'::int2vector from generate_series(1,5)));
+select array(select '11 22 33'::int2vector from generate_series(1,5));
+select unnest(array(select '11 22 33'::int2vector from generate_series(1,5)));
+select pg_typeof(array(select '11 22 33'::oidvector from generate_series(1,5)));
+select array(select '11 22 33'::oidvector from generate_series(1,5));
+select unnest(array(select '11 22 33'::oidvector from generate_series(1,5)));
+
+-- array[] should do the same
+select pg_typeof(array['11 22 33'::int2vector]);
+select array['11 22 33'::int2vector];
+select pg_typeof(unnest(array['11 22 33'::int2vector]));
+select unnest(array['11 22 33'::int2vector]);
+select pg_typeof(unnest('11 22 33'::int2vector));
+select unnest('11 22 33'::int2vector);
+select pg_typeof(array['11 22 33'::oidvector]);
+select array['11 22 33'::oidvector];
+select pg_typeof(unnest(array['11 22 33'::oidvector]));
+select unnest(array['11 22 33'::oidvector]);
+select pg_typeof(unnest('11 22 33'::oidvector));
+select unnest('11 22 33'::oidvector);
+
 -- Insert/update on a column that is array of composite
 
 create temp table t1 (f1 int8_tbl[]);