KML description: max/min elevation will not show if have invalid values (unknow).

src/main/java/de/dennisguse/opentracks/content/DescriptionGenerator.java

@@ -126,10 +126,14 @@ public class DescriptionGenerator {
         writePace(stats.getMaxSpeed(), builder, R.string.description_fastest_pace_in_minute, lineBreak);
 
         // Max elevation
-        writeElevation(stats.getMaxElevation(), builder, R.string.description_max_elevation, lineBreak);
+        if (stats.hasElevationMax()) {
+            writeElevation(stats.getMaxElevation(), builder, R.string.description_max_elevation, lineBreak);
+        }
 
         // Min elevation
-        writeElevation(stats.getMinElevation(), builder, R.string.description_min_elevation, lineBreak);
+        if (stats.hasElevationMin()) {
+            writeElevation(stats.getMinElevation(), builder, R.string.description_min_elevation, lineBreak);
+        }
 
         // Elevation gain
         writeElevation(stats.getTotalElevationGain(), builder, R.string.description_elevation_gain, lineBreak);

src/main/java/de/dennisguse/opentracks/io/file/importer/AbstractFileTrackImporter.java

@@ -313,6 +313,9 @@ abstract class AbstractFileTrackImporter extends DefaultHandler implements Track
      */
     protected TrackPoint getTrackPoint() throws SAXException {
         TrackPoint trackPoint = createTrackPoint();
+        if (trackPoint == null) {
+            throw new SAXException(createErrorMessage("Invalid location detected: " + trackPoint));
+        }
 
         // Calculate derived attributes from the previous point
         if (trackData.lastLocationInCurrentSegment != null && trackData.lastLocationInCurrentSegment.getTime() != 0) {

src/main/java/de/dennisguse/opentracks/stats/TrackStatistics.java

@@ -176,6 +176,10 @@ public class TrackStatistics {
         this.maxSpeed_mps = maxSpeed;
     }
 
+    public boolean hasElevationMin() {
+        return !Double.isInfinite(getMinElevation());
+    }
+
     /**
      * Gets the minimum elevation.
      * This is calculated from the smoothed elevation, so this can actually be more than the current elevation.
@@ -193,6 +197,10 @@ public class TrackStatistics {
         elevationExtremities.setMin(elevation);
     }
 
+    public boolean hasElevationMax() {
+        return !Double.isInfinite(getMaxElevation());
+    }
+
     /**
      * Gets the maximum elevation.
      * This is calculated from the smoothed elevation, so this can actually be less than the current elevation.