Merge pull request #390 from HSLdevcom/zero-split-elevation-extension-nan-fix

Fix bug where edge is split 0/100 and dividing 0 by 0 causes a NaN in elevation data

Author: optionsome

street/src/main/java/org/opentripplanner/street/model/edge/StreetEdge.java

@@ -773,7 +773,7 @@ protected void copyPropertiesToSplitEdge(
     );
 
     StreetElevationExtensionBuilder.of(seb)
-      .withDistanceInMeters(defaultMillimeterLength(seb.geometry()) / 1000.)
+      .withDistanceInMeters(toDistance - fromDistance)
       .withElevationProfile(partialElevationProfileFromParent)
       .build()
       .ifPresent(seb::withElevationExtension);

street/src/main/java/org/opentripplanner/street/model/edge/StreetElevationExtensionBuilder.java

@@ -43,7 +43,11 @@ public static StreetElevationExtensionBuilder of(StreetEdgeBuilder<?> seb) {
   }
 
   public Optional<StreetElevationExtension> build() {
-    if (elevationProfileHasAtLeastTwoPoints() && (!isSlopeOverride || computed)) {
+    if (
+      distanceInMeters > 0.01 &&
+      elevationProfileHasAtLeastTwoPoints() &&
+      (!isSlopeOverride || computed)
+    ) {
       return Optional.of(buildInternal());
     }
     return Optional.empty();