Fixed CRASH due to NullPointerException when a details actitivity is brough to foreground and the OC icon is pressed, after removing accounts in system settings

src/com/owncloud/android/AccountUtils.java

@@ -61,7 +61,9 @@ public class AccountUtils {
                     break;
                 }
             }
-        } else if (ocAccounts.length != 0) {
+        }
+        
+        if (defaultAccount == null && ocAccounts.length != 0) {
             // we at least need to take first account as fallback
             defaultAccount = ocAccounts[0];
         }
@@ -84,11 +86,26 @@ public class AccountUtils {
     }
     
     
-    public static void setCurrentOwnCloudAccount(Context context, String name) {
-        SharedPreferences.Editor appPrefs = PreferenceManager
-                .getDefaultSharedPreferences(context).edit();
-        appPrefs.putString("select_oc_account", name);
-        appPrefs.commit();
+    public static boolean setCurrentOwnCloudAccount(Context context, String accountName) {
+        boolean result = false;
+        if (accountName != null) {
+            Account[] ocAccounts = AccountManager.get(context).getAccountsByType(
+                    AccountAuthenticator.ACCOUNT_TYPE);
+            boolean found = false;
+            for (Account account : ocAccounts) {
+                found = (account.name.equals(accountName));
+                if (found) {
+                    SharedPreferences.Editor appPrefs = PreferenceManager
+                            .getDefaultSharedPreferences(context).edit();
+                    appPrefs.putString("select_oc_account", accountName);
+    
+                    appPrefs.commit();
+                    result = true;
+                    break;
+                }
+            }
+        }
+        return result;
     }
 
     /**

src/com/owncloud/android/ui/activity/FileDisplayActivity.java

@@ -143,10 +143,10 @@ public class FileDisplayActivity extends SherlockFragmentActivity implements
         super.onCreate(savedInstanceState);
 
         /// Load of parameters from received intent
-        mCurrentDir = getIntent().getParcelableExtra(FileDetailFragment.EXTRA_FILE); // no check necessary, mCurrenDir == null if the parameter is not in the intent
         Account account = getIntent().getParcelableExtra(FileDetailFragment.EXTRA_ACCOUNT);
-        if (account != null)
-            AccountUtils.setCurrentOwnCloudAccount(this, account.name);
+        if (account != null && AccountUtils.setCurrentOwnCloudAccount(this, account.name)) {
+            mCurrentDir = getIntent().getParcelableExtra(FileDetailFragment.EXTRA_FILE); 
+        }
         
         /// Load of saved instance state: keep this always before initDataFromCurrentAccount()
         if(savedInstanceState != null) {
@@ -187,7 +187,7 @@ public class FileDisplayActivity extends SherlockFragmentActivity implements
         // Drop-down navigation 
         mDirectories = new CustomArrayAdapter<String>(this, R.layout.sherlock_spinner_dropdown_item);
         OCFile currFile = mCurrentDir;
-        while(currFile != null && currFile.getFileName() != OCFile.PATH_SEPARATOR) {
+        while(mStorageManager != null && currFile != null && currFile.getFileName() != OCFile.PATH_SEPARATOR) {
             mDirectories.add(currFile.getFileName());
             currFile = mStorageManager.getFileById(currFile.getParentId());
         }