Merge pull request #13 from johncarl81/john/fix_durable_subscriptions

Fixes durable subscription clobbering

docker/Dockerfile

@@ -25,6 +25,10 @@ RUN echo debconf shared/accepted-oracle-license-v1-3 seen true | sudo debconf-se
 # Install Mavros, Java & ROS Bridge
 RUN apt-get -qq -y install ros-galactic-mavros oracle-java17-installer oracle-java17-set-default openjfx unzip ros-galactic-rosbridge-server libcanberra-gtk-module
 
+# Fix DURABLE subscription overreach in rosbridge
+# See https://github.com/RobotWebTools/rosbridge_suite/issues/769
+RUN sed -i '115s/RELIABLE/BEST_EFFORT/' /opt/ros/galactic/lib/python3.8/site-packages/rosbridge_library/internal/subscribers.py
+
 # Install maven
 RUN wget https://downloads.apache.org/maven/maven-3/$MAVEN_VERSION/binaries/apache-maven-${MAVEN_VERSION}-bin.tar.gz -P /tmp
 RUN tar xf /tmp/apache-maven-${MAVEN_VERSION}-bin.tar.gz -C /opt

src/main/java/edu/unm/dragonfly/Drone.java

@@ -233,7 +233,7 @@ public static class LatLonRelativeAltitude {
         public LatLonRelativeAltitude(double latitude, double longitude, double relativeAltitude) {
             this.latitude = latitude;
             this.longitude = longitude;
-            this.relativeAltitude = relativeAltitude;
+            this.relativeAltitude = relativeAltitude > 0 ? relativeAltitude : 0;
         }
 
         public double getLatitude() {