Prolog terminal: do not submit an empty query

1 files changed, 4 insertions, 0 deletions

diff --git a/js/codeq/prolog.js b/js/codeq/prolog.js
index e35984a..1d2f92e 100644
--- a/js/codeq/prolog.js
+++ b/js/codeq/prolog.js
@@ -207,6 +207,10 @@ along with this program. If not, see <http://www.gnu.org/licenses/>. */
 
         terminal.onInput = function (command) {
             if (promptMode) {
+                if (!command) {
+                    terminal.append('?- ', 'output');
+                    return;
+                }
                 promptMode = false;
                 manualStop = false;
                 terminal.setNotBuffered();