[MINOR] [UI] DAG visualization: trim whitespace from input

Just as a safeguard against DOM rewriting.

Author: Andrew Or <[email protected]>

Closes apache#6732 from andrewor14/dag-viz-trim and squashes the following commits:

7e9bacb [Andrew Or] [MINOR] [UI] DAG visualization: trim whitespace from input

Author: Andrew Or

core/src/main/resources/org/apache/spark/ui/static/spark-dag-viz.js

@@ -235,7 +235,7 @@ function renderDagVizForJob(svgContainer) {
     // them separately later. Note that we cannot draw them now because we need to
     // put these edges in a separate container that is on top of all stage graphs.
     metadata.selectAll(".incoming-edge").each(function(v) {
-      var edge = d3.select(this).text().split(","); // e.g. 3,4 => [3, 4]
+      var edge = d3.select(this).text().trim().split(","); // e.g. 3,4 => [3, 4]
       crossStageEdges.push(edge);
     });
   });