Move duckdb.row refname generation to pgduckdb_ruleutils.cpp

include/pgduckdb/pgduckdb_ruleutils.h

@@ -26,5 +26,6 @@ bool pgduckdb_function_needs_subquery(Oid function_oid);
 int pgduckdb_show_type(Const *constval, int original_showtype);
 bool pgduckdb_subscript_has_custom_alias(Plan *plan, List *rtable, Var *subscript_var, char *colname);
 SubscriptingRef *pgduckdb_strip_first_subscript(SubscriptingRef *sbsref, StringInfo buf);
+char *pgduckdb_write_row_refname(StringInfo buf, char *refname, bool is_top_level);
 
 extern bool processed_targetlist;

src/pgduckdb_ruleutils.cpp

@@ -378,6 +378,34 @@ pgduckdb_strip_first_subscript(SubscriptingRef *sbsref, StringInfo buf) {
 	return shorter_sbsref;
 }
 
+/*
+ * Writes the refname to the buf in a way that results in the correct output
+ * for the duckdb.row type.
+ *
+ * Returns the "attname" that should be passed back to the caller.
+ */
+char *
+pgduckdb_write_row_refname(StringInfo buf, char *refname, bool is_top_level) {
+	appendStringInfoString(buf, quote_identifier(refname));
+
+	if (is_top_level) {
+		/*
+		 * If the duckdb.row is at the top level target list of a select, then
+		 * we want to generate r.*, to unpack all the columns instead of
+		 * returning a STRUCT from the query.
+		 *
+		 * Since we use .* there is no attname.
+		 */
+		appendStringInfoString(buf, ".*");
+		return NULL;
+	}
+
+	/*
+	 * In any other case, we want to simply use the alias of the TargetEntry.
+	 */
+	return refname;
+}
+
 /*
  * Given a postgres schema name, this returns a list of two elements: the first
  * is the DuckDB database name and the second is the duckdb schema name. These

src/vendor/pg_ruleutils_17.c

@@ -7542,35 +7542,22 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
 		if (attnum > colinfo->num_cols)
 			elog(ERROR, "invalid attnum %d for relation \"%s\"",
 				 attnum, rte->eref->aliasname);
-		if (pgduckdb_var_is_duckdb_row(var)) {
-			if (istoplevel) {
-				/* If the duckdb row is at the top level target list of a
-				 * select, then we want to generate r.*, to unpack all the
-				 * columns instead of returning a STRUCT from the query. */
-				attname = NULL;
-			} else {
-				/* In any other case, we want to simply use the alias of the
-				 * TargetEntry, without the column name that postgres gave to
-				 * it. Because even though according to the Postgres parser we
-				 * are referencing a column of type "duckdb.row", that column
-				 * won't actually exist in the DuckDB query.
-				 */
-				attname = refname;
-				refname = NULL;
-			}
-		} else {
-			attname = colinfo->colnames[attnum - 1];
 
-			/*
-			 * If we find a Var referencing a dropped column, it seems better to
-			 * print something (anything) than to fail.  In general this should
-			 * not happen, but it used to be possible for some cases involving
-			 * functions returning named composite types, and perhaps there are
-			 * still bugs out there.
-			 */
-			if (attname == NULL)
-				attname = "?dropped?column?";
+		if (pgduckdb_var_is_duckdb_row(var)) {
+			return pgduckdb_write_row_refname(context->buf, refname, istoplevel);
 		}
+
+		attname = colinfo->colnames[attnum - 1];
+
+		/*
+		 * If we find a Var referencing a dropped column, it seems better to
+		 * print something (anything) than to fail.  In general this should
+		 * not happen, but it used to be possible for some cases involving
+		 * functions returning named composite types, and perhaps there are
+		 * still bugs out there.
+		 */
+		if (attname == NULL)
+			attname = "?dropped?column?";
 	}
 	else
 	{
@@ -7588,7 +7575,7 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
 	else
 	{
 		appendStringInfoChar(buf, '*');
-		if (istoplevel && !pgduckdb_var_is_duckdb_row(var))
+		if (istoplevel)
 			appendStringInfo(buf, "::%s",
 							 format_type_with_typemod(var->vartype,
 													  var->vartypmod));