Reject COPY FROM STDIN in extended query mode

lib/PgSQL_Session.cpp

@@ -2939,13 +2939,29 @@ handler_again:
 					}
 				}
 			}
-			// Swtich to fast forward mode if the query matches copy ... stdin command
-			re2::StringPiece matched;
-			const char* query_to_match = (CurrentQuery.get_digest_text() ? CurrentQuery.get_digest_text() : (char*)CurrentQuery.QueryPointer);
-			if (copy_cmd_matcher->match(query_to_match, &matched)) {
-				switch_normal_to_fast_forward_mode(pkt, std::string(matched.data(), matched.size()), SESSION_FORWARD_TYPE_COPY_FROM_STDIN_STDOUT);
-				break;
-			}
+			if (status == PROCESSING_QUERY || status == PROCESSING_STMT_PREPARE) {
+				// Swtich to fast forward mode if the query matches copy ... stdin command
+				re2::StringPiece matched;
+				const char* query_to_match = (CurrentQuery.get_digest_text() ? CurrentQuery.get_digest_text() : (char*)CurrentQuery.QueryPointer);
+				if (copy_cmd_matcher->match(query_to_match, &matched)) {
+
+					if (status == PROCESSING_STMT_PREPARE) {
+						reset_extended_query_frame();
+						proxy_error("'%s' command is not supported in Extended Query protocol mode. Use Simple Query mode to run this command\n",
+							query_to_match ? query_to_match : "");
+						client_myds->setDSS_STATE_QUERY_SENT_NET();
+						client_myds->myprot.generate_error_packet(true, true, "Feature not supported", PGSQL_ERROR_CODES::ERRCODE_FEATURE_NOT_SUPPORTED,
+							false, true);
+						RequestEnd(myds);
+						finishQuery(myds, myconn, false);
+						goto __exit_DSS__STATE_NOT_INITIALIZED;
+					}
+
+					switch_normal_to_fast_forward_mode(pkt , std::string(matched.data(), matched.size()), SESSION_FORWARD_TYPE_COPY_FROM_STDIN_STDOUT);
+					break;
+				}
+			} 
+
 			if (myconn->async_state_machine == ASYNC_IDLE) {
 				SetQueryTimeout();
 			}

test/tap/tests/pgsql-unsupported_feature_test-t.cpp

@@ -105,6 +105,26 @@ void check_copy_binary(PGconn* conn) {
     PQclear(res);
 }
 
+void check_copy_stdin_via_extended_query(PGconn* conn) {
+    PGresult* res = PQprepare(conn,
+        "copy_stmt",
+        "COPY mytable FROM STDIN",
+        0,
+        NULL);
+
+    ExecStatusType status = PQresultStatus(res);
+
+    /* Check that it failed */
+    ok(status == PGRES_FATAL_ERROR, "PQprepare fails for COPY FROM STDIN");
+
+    const char* sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
+
+    ok(sqlstate && strcmp(sqlstate, "0A000") == 0,
+        "SQLSTATE is 0A000 (feature_not_supported)");
+
+    PQclear(res);
+}
+
 void execute_tests(bool with_ssl) {
     PGconn* conn = create_new_connection(with_ssl);
 
@@ -117,14 +137,16 @@ void execute_tests(bool with_ssl) {
     // Test 2: COPY in binary mode
     //check_copy_binary(conn);
 
-    // Close the connection
+	// Test 3: COPY FROM STDIN via extended query
+	check_copy_stdin_via_extended_query(conn);
 
+    // Close the connection
     PQfinish(conn);
 }
 
 int main(int argc, char** argv) {
 
-    plan(1); // Total number of tests planned
+    plan(3); // Total number of tests planned
 
     if (cl.getEnv())
         return exit_status();