Fix deserializing ProjectSettings from previous GRIP versions

When opening projects with missing settings, we should use the default
values for those settings.  By default, XStream sets them to null, but
we can override that using `PureJavaReflectionProvider`.

Closes #491

Author: ThomasJClark

core/src/main/java/edu/wpi/grip/core/serialization/Project.java

@@ -2,6 +2,7 @@
 
 import com.google.common.eventbus.EventBus;
 import com.thoughtworks.xstream.XStream;
+import com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider;
 import edu.wpi.grip.core.*;
 import edu.wpi.grip.core.sources.CameraSource;
 import edu.wpi.grip.core.sources.ImageFileSource;
@@ -22,10 +23,8 @@ public class Project {
     private EventBus eventBus;
     @Inject
     private Pipeline pipeline;
-    @Inject
-    private Palette palette;
 
-    protected final XStream xstream = new XStream();
+    protected final XStream xstream = new XStream(new PureJavaReflectionProvider());
     private Optional<File> file = Optional.empty();
 
     @Inject

core/src/test/java/edu/wpi/grip/core/serialization/ProjectTest.java

@@ -22,6 +22,7 @@
 import java.io.StringWriter;
 import java.io.Writer;
 
+import static junit.framework.Assert.assertNotNull;
 import static junit.framework.TestCase.assertEquals;
 import static org.bytedeco.javacpp.opencv_core.*;
 
@@ -142,7 +143,7 @@ public void testPerformSerializedStep() throws Exception {
         serializeAndDeserialize();
 
 
-        final Step fromPipeline =  pipeline.getSteps().get(0);
+        final Step fromPipeline = pipeline.getSteps().get(0);
         InputSocket<Number> a = (InputSocket<Number>) fromPipeline.getInputSockets()[0];
         InputSocket<Number> b = (InputSocket<Number>) fromPipeline.getInputSockets()[1];
         OutputSocket<Number> sum = (OutputSocket<Number>) fromPipeline.getOutputSockets()[0];
@@ -161,7 +162,7 @@ public void testPerformSerializedPythonStepFromURL() throws Exception {
         pipeline.addStep(stepFactory.create(pythonAdditionOperationFromURL));
         serializeAndDeserialize();
 
-        final Step fromPipeline =  pipeline.getSteps().get(0);
+        final Step fromPipeline = pipeline.getSteps().get(0);
         InputSocket<Number> a = (InputSocket<Number>) fromPipeline.getInputSockets()[0];
         InputSocket<Number> b = (InputSocket<Number>) fromPipeline.getInputSockets()[1];
         OutputSocket<Number> sum = (OutputSocket<Number>) fromPipeline.getOutputSockets()[0];
@@ -181,7 +182,7 @@ public void testPerformSerializedPythonStepFromSource() throws Exception {
         pipeline.addStep(stepFactory.create(pythonAdditionOperationFromSource));
         serializeAndDeserialize();
 
-        final Step fromPipeline =  pipeline.getSteps().get(0);
+        final Step fromPipeline = pipeline.getSteps().get(0);
         InputSocket<Number> a = (InputSocket<Number>) fromPipeline.getInputSockets()[0];
         InputSocket<Number> b = (InputSocket<Number>) fromPipeline.getInputSockets()[1];
         OutputSocket<Number> sum = (OutputSocket<Number>) fromPipeline.getOutputSockets()[0];
@@ -218,7 +219,6 @@ public void testPerformSerializedPipeline() throws Exception {
         OutputSocket<Number> sum2 = (OutputSocket<Number>) step2Out.getOutputSockets()[0];
 
 
-
         a1.setValue(123);
         b1.setValue(456);
         b2.setValue(789);
@@ -240,7 +240,6 @@ public void testPerformSerializedPipelineWithMats() throws Exception {
         OutputSocket<Mat> sum = (OutputSocket<Mat>) step1.getOutputSockets()[0];
 
 
-
         a.setValue(new Mat(1, 1, CV_32F, new Scalar(1234.5)));
         b.setValue(new Mat(1, 1, CV_32F, new Scalar(6789.0)));
 
@@ -280,4 +279,18 @@ public void testSerializedProjectSettings() {
         assertEquals("Deploy address was not serialized/deserialized",
                 "roborio-191-frc.local", pipeline.getProjectSettings().getDeployAddress());
     }
+
+    @Test
+    public void testUnspecifiedProjectSettings() {
+        Reader reader = new StringReader("<grip:Pipeline>" +
+                "  <sources/>" +
+                "  <steps/>" +
+                "  <connections/>" +
+                "  <settings/>" +
+                "</grip:Pipeline>");
+
+        project.open(reader);
+
+        assertNotNull("Project setting was null", pipeline.getProjectSettings().getDeployJvmOptions());
+    }
 }