Check for null when stripping carriage returns

app/src/androidTest/java/org/tasks/ui/DescriptionControlSetTest.java

@@ -1,6 +1,7 @@
 package org.tasks.ui;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 import static org.tasks.ui.DescriptionControlSet.stripCarriageReturns;
 
 import androidx.test.ext.junit.runners.AndroidJUnit4;
@@ -23,4 +24,9 @@ public class DescriptionControlSetTest {
   public void dontReplaceLF() {
     assertEquals("aaa\nbbb", stripCarriageReturns("aaa\nbbb"));
   }
+
+  @Test
+  public void checkIfNull() {
+    assertNull(stripCarriageReturns(null));
+  }
 }

app/src/main/java/org/tasks/ui/DescriptionControlSet.java

@@ -28,8 +28,8 @@ public class DescriptionControlSet extends TaskEditControlFragment {
 
   private String description;
 
-  static String stripCarriageReturns(String original) {
-    return original.replaceAll("\\r\\n?", "\n");
+  static String stripCarriageReturns(@Nullable String original) {
+    return original == null ? null : original.replaceAll("\\r\\n?", "\n");
   }
 
   @Nullable