Fix ruleutils.c's dumping of whole-row Vars in more contexts.

tglsfdc · tglsfdc · commit 3a1bfe256575 · 2022-01-13T17:49:26.000-05:00
Commit 7745bc3 intended to ensure that whole-row Vars would be printed with "::type" decoration in all contexts where plain "var.*" notation would result in star-expansion, notably in ROW() and VALUES() constructs. However, it missed the case of INSERT with a single-row VALUES, as reported by Timur Khanjanov. Nosing around ruleutils.c, I found a second oversight: the code for RowCompareExpr generates ROW() notation without benefit of an actual RowExpr, and naturally it wasn't in sync :-(. (The code for FieldStore also does this, but we don't expect that to generate strictly parsable SQL anyway, so I left it alone.) Back-patch to all supported branches. Discussion: https://postgr.es/m/efaba6f9-4190-56be-8ff2-7a1674f9194f@intrans.baku.az
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
@@ -420,6 +420,8 @@ static void get_rule_expr(Node *node, deparse_context *context,
 			  bool showimplicit);
 static void get_rule_expr_toplevel(Node *node, deparse_context *context,
 					   bool showimplicit);
+static void get_rule_list_toplevel(List *lst, deparse_context *context,
+								   bool showimplicit);
 static void get_rule_expr_funccall(Node *node, deparse_context *context,
 					   bool showimplicit);
 static bool looks_like_function(Node *node);
@@ -6205,7 +6207,7 @@ get_insert_query_def(Query *query, deparse_context *context)
 		/* Add the single-VALUES expression list */
 		appendContextKeyword(context, "VALUES (",
 							 -PRETTYINDENT_STD, PRETTYINDENT_STD, 2);
-		get_rule_expr((Node *) strippedexprs, context, false);
+		get_rule_list_toplevel(strippedexprs, context, false);
 		appendStringInfoChar(buf, ')');
 	}
 	else
@@ -8389,23 +8391,15 @@ get_rule_expr(Node *node, deparse_context *context,
 		case T_RowCompareExpr:
 			{
 				RowCompareExpr *rcexpr = (RowCompareExpr *) node;
-				ListCell   *arg;
-				char	   *sep;
 
 				/*
 				 * SQL99 allows "ROW" to be omitted when there is more than
-				 * one column, but for simplicity we always print it.
+				 * one column, but for simplicity we always print it.  Within
+				 * a ROW expression, whole-row Vars need special treatment, so
+				 * use get_rule_list_toplevel.
 				 */
 				appendStringInfoString(buf, "(ROW(");
-				sep = "";
-				foreach(arg, rcexpr->largs)
-				{
-					Node	   *e = (Node *) lfirst(arg);
-
-					appendStringInfoString(buf, sep);
-					get_rule_expr(e, context, true);
-					sep = ", ";
-				}
+				get_rule_list_toplevel(rcexpr->largs, context, true);
 
 				/*
 				 * We assume that the name of the first-column operator will
@@ -8418,15 +8412,7 @@ get_rule_expr(Node *node, deparse_context *context,
 								 generate_operator_name(linitial_oid(rcexpr->opnos),
 														exprType(linitial(rcexpr->largs)),
 														exprType(linitial(rcexpr->rargs))));
-				sep = "";
-				foreach(arg, rcexpr->rargs)
-				{
-					Node	   *e = (Node *) lfirst(arg);
-
-					appendStringInfoString(buf, sep);
-					get_rule_expr(e, context, true);
-					sep = ", ";
-				}
+				get_rule_list_toplevel(rcexpr->rargs, context, true);
 				appendStringInfoString(buf, "))");
 			}
 			break;
@@ -8971,6 +8957,32 @@ get_rule_expr_toplevel(Node *node, deparse_context *context,
 		get_rule_expr(node, context, showimplicit);
 }
 
+/*
+ * get_rule_list_toplevel		- Parse back a list of toplevel expressions
+ *
+ * Apply get_rule_expr_toplevel() to each element of a List.
+ *
+ * This adds commas between the expressions, but caller is responsible
+ * for printing surrounding decoration.
+ */
+static void
+get_rule_list_toplevel(List *lst, deparse_context *context,
+					   bool showimplicit)
+{
+	const char *sep;
+	ListCell   *lc;
+
+	sep = "";
+	foreach(lc, lst)
+	{
+		Node	   *e = (Node *) lfirst(lc);
+
+		appendStringInfoString(context->buf, sep);
+		get_rule_expr_toplevel(e, context, showimplicit);
+		sep = ", ";
+	}
+}
+
 /*
  * get_rule_expr_funccall		- Parse back a function-call expression
  *
diff --git a/src/test/regress/expected/create_view.out b/src/test/regress/expected/create_view.out
@@ -1612,6 +1612,22 @@ select * from int8_tbl i where i.* in (values(i.*::int8_tbl));
  4567890123456789 | -4567890123456789
 (5 rows)
 
+create table tt15v_log(o tt15v, n tt15v, incr bool);
+create rule updlog as on update to tt15v do also
+  insert into tt15v_log values(old, new, row(old,old) < row(new,new));
+\d+ tt15v
+                             View "testviewschm2.tt15v"
+ Column |      Type       | Collation | Nullable | Default | Storage  | Description 
+--------+-----------------+-----------+----------+---------+----------+-------------
+ row    | nestedcomposite |           |          |         | extended | 
+View definition:
+ SELECT ROW(i.*::int8_tbl)::nestedcomposite AS "row"
+   FROM int8_tbl i;
+Rules:
+ updlog AS
+    ON UPDATE TO tt15v DO  INSERT INTO tt15v_log (o, n, incr)
+  VALUES (old.*::tt15v, new.*::tt15v, (ROW(old.*::tt15v, old.*::tt15v) < ROW(new.*::tt15v, new.*::tt15v)))
+
 -- check unique-ification of overlength names
 create view tt18v as
   select * from int8_tbl xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxy
@@ -1756,4 +1772,4 @@ select pg_get_ruledef(oid, true) from pg_rewrite
 DROP SCHEMA temp_view_test CASCADE;
 NOTICE:  drop cascades to 27 other objects
 DROP SCHEMA testviewschm2 CASCADE;
-NOTICE:  drop cascades to 63 other objects
+NOTICE:  drop cascades to 64 other objects
diff --git a/src/test/regress/sql/create_view.sql b/src/test/regress/sql/create_view.sql
@@ -548,6 +548,11 @@ select * from tt17v;
 select pg_get_viewdef('tt17v', true);
 select * from int8_tbl i where i.* in (values(i.*::int8_tbl));
 
+create table tt15v_log(o tt15v, n tt15v, incr bool);
+create rule updlog as on update to tt15v do also
+  insert into tt15v_log values(old, new, row(old,old) < row(new,new));
+\d+ tt15v
+
 -- check unique-ification of overlength names
 
 create view tt18v as
