[ivette] When jumping to a function, resets the selected marker to null.

The ASTinfo component clears the buffer when the selected marker changes and
no data is provided (which happens when the marker is null).

ivette/src/renderer/ASTinfo.tsx

@@ -23,15 +23,15 @@ const ASTinfo = () => {
 
   React.useEffect(() => {
     buffer.clear();
-    if (data) {
+    if (marker && data) {
       buffer.printTextWithTags(data, { css: 'color: blue' });
     }
-  }, [buffer, data]);
+  }, [marker, buffer, data]);
 
   // Callbacks
   function onSelection(name: string) {
     // For now, the only markers are functions.
-    setSelect({ function: name });
+    setSelect({ function: name, marker: null });
   }
 
   // Component

ivette/src/renderer/ASTview.tsx

@@ -105,7 +105,7 @@ const ASTview = () => {
     if (marker && marker.kind === 'function') {
       const item1 = {
         label: `Go to definition of ${marker.name}`,
-        onClick: () => setSelect({ function: marker.name }),
+        onClick: () => setSelect({ function: marker.name, marker: null }),
       };
       Dome.popupMenu([item1]);
     }