Update ruleutils_95 with latest PostgreSQL changes

Hand-applied changes from a diff I generated between 9.5.0 and 9.5.4.

src/backend/distributed/utils/ruleutils_95.c

@@ -1,6 +1,6 @@
 /*-------------------------------------------------------------------------
  *
- * citus_ruleutils.c
+ * ruleutils_95.c
  *	  Additional, non core exposed, functions to convert stored
  *    expressions/querytrees back to source text
  *
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  src/backend/distributed/utils/citus_ruleutils.c
+ *	  src/backend/distributed/utils/ruleutils_95.c
  *
  * This needs to be closely in sync with the core code.
  *-------------------------------------------------------------------------
@@ -3062,25 +3062,24 @@ get_insert_query_def(Query *query, deparse_context *context)
 			/* Add a WHERE clause (for partial indexes) if given */
 			if (confl->arbiterWhere != NULL)
 			{
-				bool varprefixInitialValue = context->varprefix;
+				bool		save_varprefix;
+
+				/*
+				 * Force non-prefixing of Vars, since parser assumes that they
+				 * belong to target relation.  WHERE clause does not use
+				 * InferenceElem, so this is separately required.
+				 */
+				save_varprefix = context->varprefix;
+				context->varprefix = false;
 
 				appendContextKeyword(context, " WHERE ",
 									 -PRETTYINDENT_STD, PRETTYINDENT_STD, 1);
-
-				/*
-				 * Postgres deparses arbiter WHERE clauses incorrectly. It adds
-				 * varprefix to the arbiter WHERE clause, for which Postgres parser
-				 * errors out. Thus, we temporarily set varprefix to false.
-				 */
-				context->varprefix = false;
-
 				get_rule_expr(confl->arbiterWhere, context, false);
 
-				/* now set the varprefix back to its initial value */
+				context->varprefix = save_varprefix;
-				context->varprefix = varprefixInitialValue;
 			}
 		}
-		else if (confl->constraint != InvalidOid)
+		else if (OidIsValid(confl->constraint))
 		{
 			char	   *constraint = get_constraint_name(confl->constraint);
 			int64 shardId = context->shardid;
@@ -3090,8 +3089,11 @@ get_insert_query_def(Query *query, deparse_context *context)
 				AppendShardIdToName(&constraint, shardId);
 			}
 
+			if (!constraint)
+				elog(ERROR, "cache lookup failed for constraint %u",
+					 confl->constraint);
 			appendStringInfo(buf, " ON CONSTRAINT %s",
-							 quote_qualified_identifier(NULL, constraint));
+							 quote_identifier(constraint));
 		}
 
 		if (confl->action == ONCONFLICT_NOTHING)
@@ -3592,7 +3594,8 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
 
 		tle = get_tle_by_resno(dpns->inner_tlist, var->varattno);
 		if (!tle)
-			elog(ERROR, "bogus varattno for subquery var: %d", var->varattno);
+			elog(ERROR, "invalid attnum %d for relation \"%s\"",
+				 var->varattno, rte->eref->aliasname);
 
 		Assert(netlevelsup == 0);
 		push_child_plan(dpns, dpns->inner_planstate, &save_dpns);
@@ -3653,9 +3656,13 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
 	else if (attnum > 0)
 	{
 		/* Get column name to use from the colinfo struct */
-		Assert(attnum <= colinfo->num_cols);
+		if (attnum > colinfo->num_cols)
+			elog(ERROR, "invalid attnum %d for relation \"%s\"",
+				 attnum, rte->eref->aliasname);
 		attname = colinfo->colnames[attnum - 1];
-		Assert(attname != NULL);
+		if (attname == NULL)	/* dropped column? */
+			elog(ERROR, "invalid attnum %d for relation \"%s\"",
+				 attnum, rte->eref->aliasname);
 	}
 	else if (GetRangeTblKind(rte) == CITUS_RTE_SHARD)
 	{
@@ -4791,6 +4798,24 @@ get_rule_expr(Node *node, deparse_context *context,
 									  get_base_element_type(exprType(arg2))),
 								 expr->useOr ? "ANY" : "ALL");
 				get_rule_expr_paren(arg2, context, true, node);
+
+				/*
+				 * There's inherent ambiguity in "x op ANY/ALL (y)" when y is
+				 * a bare sub-SELECT.  Since we're here, the sub-SELECT must
+				 * be meant as a scalar sub-SELECT yielding an array value to
+				 * be used in ScalarArrayOpExpr; but the grammar will
+				 * preferentially interpret such a construct as an ANY/ALL
+				 * SubLink.  To prevent misparsing the output that way, insert
+				 * a dummy coercion (which will be stripped by parse analysis,
+				 * so no inefficiency is added in dump and reload).  This is
+				 * indeed most likely what the user wrote to get the construct
+				 * accepted in the first place.
+				 */
+				if (IsA(arg2, SubLink) &&
+					((SubLink *) arg2)->subLinkType == EXPR_SUBLINK)
+					appendStringInfo(buf, "::%s",
+									 format_type_with_typemod(exprType(arg2),
+														  exprTypmod(arg2)));
 				appendStringInfoChar(buf, ')');
 				if (!PRETTY_PAREN(context))
 					appendStringInfoChar(buf, ')');
@@ -5452,17 +5477,43 @@ get_rule_expr(Node *node, deparse_context *context,
 				if (!PRETTY_PAREN(context))
 					appendStringInfoChar(buf, '(');
 				get_rule_expr_paren((Node *) ntest->arg, context, true, node);
-				switch (ntest->nulltesttype)
+
+				/*
+				 * For scalar inputs, we prefer to print as IS [NOT] NULL,
+				 * which is shorter and traditional.  If it's a rowtype input
+				 * but we're applying a scalar test, must print IS [NOT]
+				 * DISTINCT FROM NULL to be semantically correct.
+				 */
+				if (ntest->argisrow ||
+					!type_is_rowtype(exprType((Node *) ntest->arg)))
 				{
-					case IS_NULL:
+					switch (ntest->nulltesttype)
-						appendStringInfoString(buf, " IS NULL");
+					{
-						break;
+						case IS_NULL:
-					case IS_NOT_NULL:
+							appendStringInfoString(buf, " IS NULL");
-						appendStringInfoString(buf, " IS NOT NULL");
+							break;
-						break;
+						case IS_NOT_NULL:
-					default:
+							appendStringInfoString(buf, " IS NOT NULL");
-						elog(ERROR, "unrecognized nulltesttype: %d",
+							break;
-							 (int) ntest->nulltesttype);
+						default:
+							elog(ERROR, "unrecognized nulltesttype: %d",
+								 (int) ntest->nulltesttype);
+					}
+				}
+				else
+				{
+					switch (ntest->nulltesttype)
+					{
+						case IS_NULL:
+							appendStringInfoString(buf, " IS NOT DISTINCT FROM NULL");
+							break;
+						case IS_NOT_NULL:
+							appendStringInfoString(buf, " IS DISTINCT FROM NULL");
+							break;
+						default:
+							elog(ERROR, "unrecognized nulltesttype: %d",
+								 (int) ntest->nulltesttype);
+					}
 				}
 				if (!PRETTY_PAREN(context))
 					appendStringInfoChar(buf, ')');
@@ -5550,13 +5601,14 @@ get_rule_expr(Node *node, deparse_context *context,
 		case T_InferenceElem:
 			{
 				InferenceElem *iexpr = (InferenceElem *) node;
-				bool		varprefix = context->varprefix;
+				bool		save_varprefix;
 				bool		need_parens;
 
 				/*
 				 * InferenceElem can only refer to target relation, so a
-				 * prefix is never useful.
+				 * prefix is not useful, and indeed would cause parse errors.
 				 */
+				save_varprefix = context->varprefix;
 				context->varprefix = false;
 
 				/*
@@ -5576,7 +5628,7 @@ get_rule_expr(Node *node, deparse_context *context,
 				if (need_parens)
 					appendStringInfoChar(buf, ')');
 
-				context->varprefix = varprefix;
+				context->varprefix = save_varprefix;
 
 				if (iexpr->infercollid)
 					appendStringInfo(buf, " COLLATE %s",
@@ -7331,4 +7383,4 @@ generate_operator_name(Oid operid, Oid arg1, Oid arg2)
 	return buf.data;
 }
 
-#endif
+#endif /* (PG_VERSION_NUM >= 90500 && PG_VERSION_NUM < 90600) */