Issue 318

When performing a database upgrade, clear all cached attachments and
attachment thumbnails

src/com/android/email/mail/store/LocalStore.java

@@ -94,23 +94,35 @@ public class LocalStore extends Store implements Serializable {
         if (!parentDir.exists()) {
             parentDir.mkdirs();
         }
-        mDb = SQLiteDatabase.openOrCreateDatabase(mPath, null);
-        if (mDb.getVersion() != DB_VERSION) {
-            doDbUpgrade(mDb);
-        }
-
         
         mAttachmentsDir = new File(mPath + "_att");
         if (!mAttachmentsDir.exists()) {
             mAttachmentsDir.mkdirs();
         }
+        
+        mDb = SQLiteDatabase.openOrCreateDatabase(mPath, null);
+        if (mDb.getVersion() != DB_VERSION) {
+            doDbUpgrade(mDb, application);
+        }
+        
     }
 
     
-    private void doDbUpgrade ( SQLiteDatabase mDb) {
+    private void doDbUpgrade ( SQLiteDatabase mDb, Application application) {
             Log.i(Email.LOG_TAG, String.format("Upgrading database from version %d to version %d", 
                 mDb.getVersion(), DB_VERSION));
             
+            try
+            {
+              pruneCachedAttachments(true);
+            }
+            catch (MessagingException me)
+            {
+              Log.e(Email.LOG_TAG, "Exception while force pruning attachments during DB update", me);
+            }
+            
+            AttachmentProvider.clear(application);
+            
             mDb.execSQL("DROP TABLE IF EXISTS folders");
             mDb.execSQL("CREATE TABLE folders (id INTEGER PRIMARY KEY, name TEXT, "
                     + "last_updated INTEGER, unread_count INTEGER, visible_limit INTEGER, status TEXT)");

src/com/android/email/provider/AttachmentProvider.java

@@ -10,6 +10,7 @@ import java.util.List;
 
 import android.content.ContentProvider;
 import android.content.ContentValues;
+import android.content.Context;
 import android.database.Cursor;
 import android.database.MatrixCursor;
 import android.database.sqlite.SQLiteDatabase;
@@ -83,6 +84,21 @@ public class AttachmentProvider extends ContentProvider {
         return true;
     }
     
+    public static void clear(Context lContext) {
+      /*
+       * We use the cache dir as a temporary directory (since Android doesn't give us one) so
+       * on startup we'll clean up any .tmp files from the last run.
+       */
+      File[] files = lContext.getCacheDir().listFiles();
+      for (File file : files) {
+        try {
+          Log.d(Email.LOG_TAG, "Deleting file " + file.getCanonicalPath());
+        }
+        catch (IOException ioe) {}   // No need to log failure to log
+         file.delete();
+      }
+  }
+
     @Override
     public String getType(Uri uri) {
         List<String> segments = uri.getPathSegments();