Fix Select/Hold Browser callback with FL_WHEN_RELEASE when mouse is dragged

src/Fl_Browser_.cxx

@@ -789,6 +789,7 @@ J1:
 // This second call of Fl_Browser_::handle() may result in a -
 // somewhat unexpected - second concurrent invocation of the callback.
 
+  static void* initsel;
   static char change;
   static char whichway;
   static int py;
@@ -800,6 +801,7 @@ J1:
       redraw();
     }
     my = py = Fl::event_y();
+    initsel = selection_;
     change = 0;
     if (type() == FL_NORMAL_BROWSER || !top_)
       ;
@@ -904,11 +906,10 @@ J1:
       }
       if (l) selection_ = l;
     } else {
-      void* l1 = selection_;
       void* l =
         (Fl::event_x()<x() || Fl::event_x()>x()+w()) ? selection_ :
         find_item(my);
-      change = (l != l1);
+      change = (l != initsel);
       select_only(l, when() & FL_WHEN_CHANGED);
       if (wp.deleted()) return 1;
     }