Fixed issue #48

src/de/danoeh/antennapod/storage/DownloadRequester.java

@@ -49,10 +49,10 @@ public static DownloadRequester getInstance() {
 	private void download(Context context, FeedFile item, File dest,
 			boolean overwriteIfExists) {
 		if (!isDownloadingFile(item)) {
-			if (dest.exists()) {
+			if (!isFilenameAvailable(dest.toString()) || dest.exists()) {
 				if (AppConfig.DEBUG)
-					Log.d(TAG, "File already exists.");
-				if (overwriteIfExists) {
+					Log.d(TAG, "Filename already used.");
+				if (isFilenameAvailable(dest.toString()) && overwriteIfExists) {
 					boolean result = dest.delete();
 					if (AppConfig.DEBUG)
 						Log.d(TAG, "Deleting file. Result: " + result);
@@ -69,7 +69,7 @@ private void download(Context context, FeedFile item, File dest,
 						if (AppConfig.DEBUG)
 							Log.d(TAG, "Testing filename " + newName);
 						newDest = new File(dest.getParent(), newName);
-						if (!newDest.exists()) {
+						if (!newDest.exists() && isFilenameAvailable(newDest.toString())) {
 							if (AppConfig.DEBUG)
 								Log.d(TAG, "File doesn't exist yet. Using "
 										+ newName);
@@ -108,6 +108,24 @@ private void download(Context context, FeedFile item, File dest,
 		}
 	}
 
+	/**
+	 * Returns true if a filename is available and false if it has already been
+	 * taken by another requested download.
+	 */
+	private boolean isFilenameAvailable(String path) {
+		for (String key : downloads.keySet()) {
+			FeedFile f = downloads.get(key);
+			if (f.getFile_url().equals(path)) {
+				if (AppConfig.DEBUG)
+					Log.d(TAG, path
+							+ " is already used by another requested download");
+				return false;
+			}
+		}
+		if (AppConfig.DEBUG) Log.d(TAG, path + " is available as a download destination");
+		return true;
+	}
+
 	public void downloadFeed(Context context, Feed feed)
 			throws DownloadRequestException {
 		if (feedFileValid(feed)) {