use _replotting in cartesian dragbox

Author: alexcjohnson

src/plots/cartesian/dragbox.js

@@ -516,6 +516,9 @@ function makeDragBox(gd, plotinfo, x, y, w, h, ns, ew) {
             return;
         }
 
+        // prevent axis drawing from monkeying with margins until we're done
+        gd._fullLayout._replotting = true;
+
         if(xActive === 'ew' || yActive === 'ns') {
             if(xActive) dragAxList(xaxes, dx);
             if(yActive) dragAxList(yaxes, dy);
@@ -726,7 +729,10 @@ function makeDragBox(gd, plotinfo, x, y, w, h, ns, ew) {
         // accumulated MathJax promises - wait for them before we relayout.
         Lib.syncOrAsync([
             Plots.previousPromises,
-            function() { Registry.call('_guiRelayout', gd, updates); }
+            function() {
+                gd._fullLayout._replotting = false;
+                Registry.call('_guiRelayout', gd, updates);
+            }
         ], gd);
     }