Fixed bug CORE-2943 : parsing error recursive query with two recursiv…

…e parts

src/dsql/dsql.h

@@ -520,6 +520,8 @@ class CompiledStatement : public dsql_req
 	// CTE name or via alias. We need to substitute this aliases when processing CTE
 	// member to resolve field names. Therefore we store all aliases in order of
 	// occurrence and later use it in backward order (since our parser is right-to-left).
+	// Also we put CTE name after all such aliases to distinguish aliases for 
+	// different CTE's.
 	// We also need to repeat this process if main select expression contains union with
 	// recursive CTE
 	void addCTEAlias(const dsql_str* alias)
@@ -530,9 +532,21 @@ class CompiledStatement : public dsql_req
 	{
 		return *(--req_curr_cte_alias);
 	}
-	void resetCTEAlias()
+	void resetCTEAlias(const dsql_str* alias)
 	{
-		req_curr_cte_alias = req_cte_aliases.end();
+		const dsql_str* const* begin = req_cte_aliases.begin();
+
+		req_curr_cte_alias = req_cte_aliases.end() - 1;
+		fb_assert(req_curr_cte_alias >= begin);
+
+		const dsql_str* curr = *(req_curr_cte_alias);
+		while (strcmp(curr->str_data, alias->str_data)) 
+		{
+			req_curr_cte_alias--;
+			fb_assert(req_curr_cte_alias >= begin);
+
+			curr = *(req_curr_cte_alias);
+		}
 	}
 
 	bool isPsql() const

src/dsql/pass1.cpp

@@ -5075,7 +5075,7 @@ static dsql_nod* pass1_derived_table(CompiledStatement* statement, dsql_nod* inp
 		statement->req_recursive_ctx = context;
 		statement->req_context = &temp;
 
-		statement->resetCTEAlias();
+		statement->resetCTEAlias(alias);
 
 		rse = PASS1_rse(statement, input->nod_arg[e_derived_table_rse], NULL);
 
@@ -10717,11 +10717,17 @@ void CompiledStatement::addCTEs(dsql_nod* with)
 	{
 		fb_assert((*cte)->nod_type == nod_derived_table);
 
-		if (with->nod_flags & NOD_UNION_RECURSIVE) {
+		if (with->nod_flags & NOD_UNION_RECURSIVE) 
+		{
 			req_curr_ctes.push(*cte);
 			PsqlChanger changer(this, false);
 			req_ctes.add(pass1_recursive_cte(this, *cte));
 			req_curr_ctes.pop();
+
+			// Add CTE name into CTE aliases stack. It allows later to search for 
+			// aliases of given CTE.
+			const dsql_str* cte_name = (dsql_str*) (*cte)->nod_arg[e_derived_table_alias];
+			addCTEAlias(cte_name);
 		}
 		else {
 			req_ctes.add(*cte);