More potential protection against null pointer exceptions when an atom feed url is not available.

app/src/main/java/com/commit451/gitlab/activity/UserActivity.java

@@ -91,7 +91,7 @@ public class UserActivity extends BaseActivity {
         if (savedInstanceState == null) {
             FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
-            fragmentTransaction.add(R.id.user_feed, FeedFragment.newInstance(mUser.getFeedUrl().toString())).commit();
+            fragmentTransaction.add(R.id.user_feed, FeedFragment.newInstance(mUser.getFeedUrl())).commit();
         }
     }

app/src/main/java/com/commit451/gitlab/adapter/GroupPagerAdapter.java

@@ -54,7 +54,7 @@ public class GroupPagerAdapter extends FragmentPagerAdapter {
         switch (position) {
             case ACTIVITY_POS:
-                return FeedFragment.newInstance(mGroup.getFeedUrl().toString());
+                return FeedFragment.newInstance(mGroup.getFeedUrl());
             case PROJECTS_POS:
                 return ProjectsFragment.newInstance(mGroup);
             case MEMBERS_POS:

app/src/main/java/com/commit451/gitlab/adapter/SectionsPagerAdapter.java

@@ -77,7 +77,7 @@ public class SectionsPagerAdapter extends FragmentPagerAdapter {
             case OVERVIEW_POS:
                 return OverviewFragment.newInstance();
             case ACTIVITY_POS:
-                return FeedFragment.newInstance(mProject.getFeedUrl().toString());
+                return FeedFragment.newInstance(mProject.getFeedUrl());
             case FILES_POS:
                 return FilesFragment.newInstance();
             case COMMITS_POS:

app/src/main/java/com/commit451/gitlab/model/api/Project.java

 package com.commit451.gitlab.model.api;
 import android.net.Uri;
+import android.support.annotation.Nullable;
 import com.google.gson.annotations.SerializedName;
@@ -188,8 +189,12 @@ public class Project {
         return mOpenIssuesCount;
     }
+    @Nullable
     public Uri getFeedUrl() {
-        return Uri.parse(mWebUrl.toString() + ".atom");
+        if (mWebUrl == null) {
+            return null;
+        }
+        return Uri.parse(mWebUrl + ".atom");
     }
     public boolean belongsToGroup() {

app/src/main/java/com/commit451/gitlab/model/api/UserBasic.java

 package com.commit451.gitlab.model.api;
+import android.net.Uri;
+import android.support.annotation.Nullable;
+
 import com.google.gson.annotations.SerializedName;
 import org.parceler.Parcel;
-import android.net.Uri;
-
 @Parcel
 public class UserBasic extends UserSafe {
     @SerializedName("id")
@@ -35,7 +36,11 @@ public class UserBasic extends UserSafe {
         return mWebUrl;
     }
+    @Nullable
     public Uri getFeedUrl() {
+        if (mWebUrl == null) {
+            return null;
+        }
         return Uri.parse(mWebUrl.toString() + ".atom");
     }