filter seen traces in period hovers

Author: archmoj

src/components/fx/hover.js

@@ -685,9 +685,18 @@ function _hover(gd, evt, subplot, noHoverEvent) {
                 findHoverPoints(customXVal, end);
             }
 
-            // remove non-period aditions
-            for(var k = hoverData.length - 1; k >= initLen; k--) {
-                if(!hoverData[k].trace[axLetter + 'period']) {
+            var k;
+            var seen = {};
+            for(k = 0; k < initLen; k++) {
+                seen[hoverData[k].trace.index] = true;
+            }
+
+            // remove non-period aditions and traces that seen before
+            for(k = hoverData.length - 1; k >= initLen; k--) {
+                if(
+                    seen[hoverData[k].trace.index] ||
+                    !hoverData[k].trace[axLetter + 'period']
+                ) {
                     hoverData.splice(k, 1);
                 }
             }