BUG 2042088 : SDK Updater: we want to keep getenv(TEMP_SDK_URL)

Renamed the getenv and added one for user sources.
Added a (naive) check to prevent duplicate URLs.

Also fixed the repositoy.xml download error message, it was not displaying the reason of failure correctly.

tools/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/repository/RepoSource.java

@@ -56,6 +56,9 @@ public class RepoSource implements IDescription {
 
     /**
      * Constructs a new source for the given repository URL.
+     * @param url The source URL. Cannot be null. If the URL ends with a /, the default
+     *            repository.xml filename will be appended automatically.
+     * @param userSource True if this a user source (add-ons & packages only.)
      */
     public RepoSource(String url, boolean userSource) {
 
@@ -72,6 +75,23 @@ public class RepoSource implements IDescription {
         setDefaultDescription();
     }
 
+    /**
+     * Two repo source are equal if they have the same userSource flag and the same URL.
+     */
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof RepoSource) {
+            RepoSource rs = (RepoSource) obj;
+            return  rs.isUserSource() == this.isUserSource() && rs.getUrl().equals(this.getUrl());
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return mUrl.hashCode() ^ Boolean.valueOf(mUserSource).hashCode();
+    }
+
     /** Returns true if this is a user source. We only load addon and extra packages
      * from a user source and ignore the rest. */
     public boolean isUserSource() {
@@ -176,7 +196,7 @@ public class RepoSource implements IDescription {
                 }
             }
 
-            monitor.setResult("Failed to fetch URL %1$s, reason:", url, reason);
+            monitor.setResult("Failed to fetch URL %1$s, reason: %2$s", url, reason);
         }
 
         monitor.incProgress(1);

tools/sdkmanager/libs/sdklib/src/com/android/sdklib/internal/repository/RepoSources.java

@@ -95,7 +95,10 @@ public class RepoSources {
                 for (int i = 0; i < count; i++) {
                     String url = props.getProperty(String.format("%s%02d", KEY_SRC, i));  //$NON-NLS-1$
                     if (url != null) {
-                        mSources.add(new RepoSource(url, true /*userSource*/));
+                        RepoSource s = new RepoSource(url, true /*userSource*/);
+                        if (!hasSource(s)) {
+                            mSources.add(s);
+                        }
                     }
                 }
             }
@@ -119,6 +122,20 @@ public class RepoSources {
         }
     }
 
+    /**
+     * Returns true if there's already a similar source in the sources list.
+     * <p/>
+     * The search is O(N), which should be acceptable on the expectedly small source list.
+     */
+    public boolean hasSource(RepoSource source) {
+        for (RepoSource s : mSources) {
+            if (s.equals(source)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     /**
      * Saves all the user sources.
      * @param log