diff --git a/DroidFish/src/org/petero/droidfish/DroidFish.java b/DroidFish/src/org/petero/droidfish/DroidFish.java
index 1b60404..c6b9af0 100644
--- a/DroidFish/src/org/petero/droidfish/DroidFish.java
+++ b/DroidFish/src/org/petero/droidfish/DroidFish.java
@@ -227,15 +227,15 @@ public class DroidFish extends Activity implements GUIInterface {
             if ((intent.getData() != null) && intent.getScheme().equals("content")) {
                 ContentResolver resolver = getContentResolver();
                 InputStream in = resolver.openInputStream(intent.getData());
-                String tmp = "";
+                StringBuilder sb = new StringBuilder();
                 while (true) {
                     byte[] buffer = new byte[16384];
                     int len = in.read(buffer);
                     if (len <= 0)
                         break;
-                    tmp += new String(buffer, 0, len);
+                    sb.append(new String(buffer, 0, len));
                 }
-                pgn = tmp;
+                pgn = sb.toString();
             }
         } catch (IOException e) {
             Toast.makeText(getApplicationContext(), "Failed to read pgn data", Toast.LENGTH_SHORT).show();
diff --git a/DroidFish/src/org/petero/droidfish/activities/PGNFile.java b/DroidFish/src/org/petero/droidfish/activities/PGNFile.java
index 0895a94..1825058 100644
--- a/DroidFish/src/org/petero/droidfish/activities/PGNFile.java
+++ b/DroidFish/src/org/petero/droidfish/activities/PGNFile.java
@@ -325,7 +325,8 @@ public class PGNFile {
             copyData(fileReader, fileWriter, fileReader.length() - gi.endPos);
             fileReader.close();
             fileWriter.close();
-            tmpFile.renameTo(fileName);
+            if (!tmpFile.renameTo(fileName))
+                throw new IOException();
 
             // Update gamesInFile
             if (gamesInFile != null) {
diff --git a/DroidFish/src/org/petero/droidfish/gamelogic/GameTree.java b/DroidFish/src/org/petero/droidfish/gamelogic/GameTree.java
index 7fe3321..c4073b5 100644
--- a/DroidFish/src/org/petero/droidfish/gamelogic/GameTree.java
+++ b/DroidFish/src/org/petero/droidfish/gamelogic/GameTree.java
@@ -29,6 +29,7 @@ import java.util.Collections;
 import java.util.GregorianCalendar;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 
 import org.petero.droidfish.PGNOptions;
 import org.petero.droidfish.gamelogic.Game.GameState;
@@ -1364,8 +1365,9 @@ public class GameTree {
     }
 
     void setHeaders(Map<String,String> headers) {
-        for (String tag : headers.keySet()) {
-            String val = headers.get(tag);
+        for (Entry<String, String> entry : headers.entrySet()) {
+            String tag = entry.getKey();
+            String val = entry.getValue();
             if (tag.equals("Event")) event = val;
             else if (tag.equals("Site")) site = val;
             else if (tag.equals("Date")) date = val;