always cancel APK download progress reports

Before, these were not being reliably canceled before the final COMPLETE or
INTERRUPTED notification went out.  This moves closing the progress Timer
to a finally block after the Timer is setup, which should hopefully
guarantee the progress reports are always stopped.

This prevents any more progress reports from being sent, in case there is
one pending anywhere. downloaderProgressListener needs to be volatile to
ensure that the two threads are seeing the same values.

This was an omission on my part when putting together the DownloaderService
in !248

app/src/main/java/org/fdroid/fdroid/net/Downloader.java

@@ -30,7 +30,6 @@ public abstract class Downloader {
     private volatile boolean cancelled = false;
     private volatile int bytesRead;
     private volatile int totalBytes;
-    private Timer timer;
 
     public final File outputFile;
 
@@ -49,7 +48,7 @@ public abstract class Downloader {
     /**
      * For sending download progress, should only be called in {@link #progressTask}
      */
-    private DownloaderProgressListener downloaderProgressListener;
+    private volatile DownloaderProgressListener downloaderProgressListener;
 
     protected abstract InputStream getDownloadersInputStream() throws IOException;
 
@@ -131,9 +130,6 @@ public abstract class Downloader {
     private void throwExceptionIfInterrupted() throws InterruptedException {
         if (cancelled) {
             Utils.debugLog(TAG, "Received interrupt, cancelling download");
-            if (timer != null) {
-                timer.cancel();
-            }
             throw new InterruptedException();
         }
     }
@@ -151,11 +147,12 @@ public abstract class Downloader {
      * progress counter.
      */
     private void copyInputToOutputStream(InputStream input, int bufferSize, OutputStream output) throws IOException, InterruptedException {
+        Timer timer = new Timer();
+        try {
             bytesRead = 0;
             totalBytes = totalDownloadSize();
             byte[] buffer = new byte[bufferSize];
 
-        timer = new Timer();
             timer.scheduleAtFixedRate(progressTask, 0, 100);
 
             // Getting the total download size could potentially take time, depending on how
@@ -181,11 +178,14 @@ public abstract class Downloader {
                 bytesRead += count;
                 output.write(buffer, 0, count);
             }
+        } finally {
+            downloaderProgressListener = null;
             timer.cancel();
             timer.purge();
             output.flush();
             output.close();
         }
+    }
 
     /**
      * Send progress updates on a timer to avoid flooding receivers with pointless events.

app/src/main/java/org/fdroid/fdroid/net/DownloaderService.java

@@ -280,7 +280,6 @@ public class DownloaderService extends Service {
             downloader.setListener(new Downloader.DownloaderProgressListener() {
                 @Override
                 public void sendProgress(URL sourceUrl, int bytesRead, int totalBytes) {
-                    if (isActive(uri.toString())) {
                     Intent intent = new Intent(Downloader.ACTION_PROGRESS);
                     intent.setData(uri);
                     intent.putExtra(Downloader.EXTRA_BYTES_READ, bytesRead);
@@ -295,7 +294,6 @@ public class DownloaderService extends Service {
                         nm.notify(NOTIFY_DOWNLOADING, notification);
                     }
                 }
-                }
             });
             downloader.download();
             sendBroadcast(uri, Downloader.ACTION_COMPLETE, localFile);