Implicitly using the default locale is a common source of bugs

internal: Locale.ROOT
otherwise Locale.getDefault()

src/gplay/java/com/owncloud/android/utils/PushUtils.java

@@ -63,6 +63,7 @@ import java.security.PublicKey;
 import java.security.spec.InvalidKeySpecException;
 import java.security.spec.PKCS8EncodedKeySpec;
 import java.security.spec.X509EncodedKeySpec;
+import java.util.Locale;
 
 public class PushUtils {
 
@@ -191,7 +192,7 @@ public class PushUtils {
         if (!TextUtils.isEmpty(MainApp.getAppContext().getResources().getString(R.string.push_server_url)) &&
                 !TextUtils.isEmpty(token)) {
             PushUtils.generateRsa2048KeyPair();
-            String pushTokenHash = PushUtils.generateSHA512Hash(token).toLowerCase();
+            String pushTokenHash = PushUtils.generateSHA512Hash(token).toLowerCase(Locale.ROOT);
             PublicKey devicePublicKey = (PublicKey) PushUtils.readKeyFromFile(true);
             if (devicePublicKey != null) {
                 byte[] publicKeyBytes = Base64.encode(devicePublicKey.getEncoded(), Base64.NO_WRAP);

src/main/java/com/owncloud/android/authentication/AuthenticatorActivity.java

@@ -130,6 +130,7 @@ import java.io.InputStream;
 import java.net.URLDecoder;
 import java.security.cert.X509Certificate;
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
@@ -330,7 +331,7 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
 
         } else {
             setContentView(R.layout.account_setup_webview);
-            mLoginWebView = (WebView) findViewById(R.id.login_webview);
+            mLoginWebView = findViewById(R.id.login_webview);
             initWebViewLogin(null);
         }
 
@@ -353,14 +354,14 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
     }
 
     private static String getWebLoginUserAgent() {
-        return Build.MANUFACTURER.substring(0, 1).toUpperCase() +
-                Build.MANUFACTURER.substring(1).toLowerCase() + " " + Build.MODEL;
+        return Build.MANUFACTURER.substring(0, 1).toUpperCase(Locale.getDefault()) +
+                Build.MANUFACTURER.substring(1).toLowerCase(Locale.getDefault()) + " " + Build.MODEL;
     }
 
     private void initWebViewLogin(String baseURL) {
         mLoginWebView.setVisibility(View.GONE);
 
-        final ProgressBar progressBar = (ProgressBar) findViewById(R.id.login_webview_progress_bar);
+        final ProgressBar progressBar = findViewById(R.id.login_webview_progress_bar);
 
         mLoginWebView.getSettings().setAllowFileAccess(false);
         mLoginWebView.getSettings().setJavaScriptEnabled(true);
@@ -572,15 +573,15 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
      * Configures elements in the user interface under direct control of the Activity.
      */
     private void initOverallUi() {
-        mHostUrlInput = (CustomEditText) findViewById(R.id.hostUrlInput);
-        mUsernameInputLayout = (TextInputLayout) findViewById(R.id.input_layout_account_username);
-        mPasswordInputLayout = (TextInputLayout) findViewById(R.id.input_layout_account_password);
-        mPasswordInput = (EditText) findViewById(R.id.account_password);
-        mUsernameInput = (EditText) findViewById(R.id.account_username);
-        mAuthStatusView = (TextView) findViewById(R.id.auth_status_text);
-        mOAuth2Check = (CheckBox) findViewById(R.id.oauth_onOff_check);
-        mServerStatusView = (TextView) findViewById(R.id.server_status_text);
-        mTestServerButton = (ImageButton) findViewById(R.id.testServerButton);
+        mHostUrlInput = findViewById(R.id.hostUrlInput);
+        mUsernameInputLayout = findViewById(R.id.input_layout_account_username);
+        mPasswordInputLayout = findViewById(R.id.input_layout_account_password);
+        mPasswordInput = findViewById(R.id.account_password);
+        mUsernameInput = findViewById(R.id.account_username);
+        mAuthStatusView = findViewById(R.id.auth_status_text);
+        mOAuth2Check = findViewById(R.id.oauth_onOff_check);
+        mServerStatusView = findViewById(R.id.server_status_text);
+        mTestServerButton = findViewById(R.id.testServerButton);
 
         mOkButton = findViewById(R.id.buttonOK);
         mOkButton.setOnClickListener(v -> onOkClick());
@@ -603,13 +604,13 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
         }
 
         /// step 2 - set properties of UI elements (text, visibility, enabled...)
-        Button welcomeLink = (Button) findViewById(R.id.welcome_link);
+        Button welcomeLink = findViewById(R.id.welcome_link);
         welcomeLink.setVisibility(mAction == ACTION_CREATE && isWelcomeLinkVisible ? View.VISIBLE : View.GONE);
         welcomeLink.setText(getString(R.string.auth_register));
 
         mTestServerButton.setVisibility(mAction == ACTION_CREATE ? View.VISIBLE : View.GONE);
 
-        TextView instructionsView = (TextView) findViewById(R.id.instructions_message);
+        TextView instructionsView = findViewById(R.id.instructions_message);
         if (instructionsMessageText != null) {
             instructionsView.setVisibility(View.VISIBLE);
             instructionsView.setText(instructionsMessageText);
@@ -665,7 +666,7 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
 
         if (!webViewLoginMethod) {
             /// step 2 - set properties of UI elements (text, visibility, enabled...)
-            mHostUrlInput = (CustomEditText) findViewById(R.id.hostUrlInput);
+            mHostUrlInput = findViewById(R.id.hostUrlInput);
             // Convert IDN to Unicode
             mHostUrlInput.setText(DisplayUtils.convertIdn(mServerInfo.mBaseUrl, false));
             if (mAction != ACTION_CREATE) {
@@ -681,7 +682,7 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
             }
             showRefreshButton(mServerIsChecked && !mServerIsValid &&
                     mWaitingForOpId > Integer.MAX_VALUE);
-            mServerStatusView = (TextView) findViewById(R.id.server_status_text);
+            mServerStatusView = findViewById(R.id.server_status_text);
             showServerStatus();
 
             /// step 3 - bind some listeners and options
@@ -741,12 +742,12 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
     private void initAuthorizationPreFragment(Bundle savedInstanceState) {
 
         /// step 0 - get UI elements in layout
-        mOAuth2Check = (CheckBox) findViewById(R.id.oauth_onOff_check);
-        mOAuthAuthEndpointText = (TextView) findViewById(R.id.oAuthEntryPoint_1);
-        mOAuthTokenEndpointText = (TextView) findViewById(R.id.oAuthEntryPoint_2);
-        mUsernameInput = (EditText) findViewById(R.id.account_username);
-        mPasswordInput = (EditText) findViewById(R.id.account_password);
-        mAuthStatusView = (TextView) findViewById(R.id.auth_status_text);
+        mOAuth2Check = findViewById(R.id.oauth_onOff_check);
+        mOAuthAuthEndpointText = findViewById(R.id.oAuthEntryPoint_1);
+        mOAuthTokenEndpointText = findViewById(R.id.oAuthEntryPoint_2);
+        mUsernameInput = findViewById(R.id.account_username);
+        mPasswordInput = findViewById(R.id.account_password);
+        mAuthStatusView = findViewById(R.id.auth_status_text);
 
         /// step 1 - load and process relevant inputs (resources, intent, savedInstanceState)
         String presetUserName = null;
@@ -1434,7 +1435,7 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
                 mPasswordInputLayout.setVisibility(View.GONE);
 
                 setContentView(R.layout.account_setup_webview);
-                mLoginWebView = (WebView) findViewById(R.id.login_webview);
+                mLoginWebView = findViewById(R.id.login_webview);
                 initWebViewLogin(mServerInfo.mBaseUrl);
             } else {
                 // show old login
@@ -1507,7 +1508,7 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
 
             case OK_NO_SSL:
             case OK:
-                if (mHostUrlInput.getText().toString().trim().toLowerCase().startsWith(HTTP_PROTOCOL)) {
+                if (mHostUrlInput.getText().toString().trim().toLowerCase(Locale.ROOT).startsWith(HTTP_PROTOCOL)) {
                     mServerStatusText = getResources().getString(R.string.auth_connection_established);
                     mServerStatusIcon = R.drawable.ic_ok;
                 } else {
@@ -1592,7 +1593,7 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
 
             case OK_NO_SSL:
             case OK:
-                if (mHostUrlInput.getText().toString().trim().toLowerCase().startsWith(HTTP_PROTOCOL)) {
+                if (mHostUrlInput.getText().toString().trim().toLowerCase(Locale.ROOT).startsWith(HTTP_PROTOCOL)) {
                     mAuthStatusText = getResources().getString(R.string.auth_connection_established);
                     mAuthStatusIcon = R.drawable.ic_ok;
                 } else {
@@ -1712,12 +1713,12 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
                 mLoginWebView.setVisibility(View.GONE);
                 setContentView(R.layout.account_setup);
 
-                CustomEditText serverAddressField = (CustomEditText) findViewById(R.id.hostUrlInput);
+                CustomEditText serverAddressField = findViewById(R.id.hostUrlInput);
                 serverAddressField.setText(mServerInfo.mBaseUrl);
 
                 findViewById(R.id.oauth_onOff_check).setVisibility(View.GONE);
                 findViewById(R.id.server_status_text).setVisibility(View.GONE);
-                mAuthStatusView = (TextView) findViewById(R.id.auth_status_text);
+                mAuthStatusView = findViewById(R.id.auth_status_text);
 
                 showAuthStatus();
             }
@@ -1749,7 +1750,7 @@ public class AuthenticatorActivity extends AccountAuthenticatorActivity
 
         } else {    // authorization fail due to client side - probably wrong credentials
             if (webViewLoginMethod) {
-                mLoginWebView = (WebView) findViewById(R.id.login_webview);
+                mLoginWebView = findViewById(R.id.login_webview);
                 initWebViewLogin(mServerInfo.mBaseUrl);
 
                 Snackbar.make(mLoginWebView, getString(R.string.auth_access_failed) + ": " + result.getLogMessage(),

src/main/java/com/owncloud/android/authentication/AuthenticatorUrlUtils.java

@@ -25,6 +25,8 @@ import com.owncloud.android.MainApp;
 import com.owncloud.android.lib.common.accounts.AccountTypeUtils;
 import com.owncloud.android.lib.resources.status.OwnCloudVersion;
 
+import java.util.Locale;
+
 /**
  * Helper class for authenticator-URL related logic.
  */
@@ -75,8 +77,8 @@ public abstract class AuthenticatorUrlUtils {
         if (normalizedUrl != null && normalizedUrl.length() > 0) {
             normalizedUrl = normalizedUrl.trim();
 
-            if (!normalizedUrl.toLowerCase().startsWith(HTTP_PROTOCOL) &&
-                    !normalizedUrl.toLowerCase().startsWith(HTTP_PROTOCOL)) {
+            if (!normalizedUrl.toLowerCase(Locale.ROOT).startsWith(HTTP_PROTOCOL) &&
+                    !normalizedUrl.toLowerCase(Locale.ROOT).startsWith(HTTP_PROTOCOL)) {
                 if (sslWhenUnprefixed) {
                     normalizedUrl = HTTPS_PROTOCOL + normalizedUrl;
                 } else {
@@ -110,7 +112,7 @@ public abstract class AuthenticatorUrlUtils {
     }
 
     private static String trimUrlWebdav(String url) {
-        if (url.toLowerCase().endsWith(WEBDAV_PATH_4_0_AND_LATER)) {
+        if (url.toLowerCase(Locale.ROOT).endsWith(WEBDAV_PATH_4_0_AND_LATER)) {
             return url.substring(0, url.length() - WEBDAV_PATH_4_0_AND_LATER.length());
         }
 

src/main/java/com/owncloud/android/datamodel/OCFile.java

@@ -34,6 +34,7 @@ import com.owncloud.android.lib.common.utils.Log_OC;
 import com.owncloud.android.utils.MimeType;
 
 import java.io.File;
+import java.util.Locale;
 
 import third_parties.daveKoeller.AlphanumComparator;
 
@@ -563,7 +564,7 @@ public class OCFile implements Parcelable, Comparable<OCFile> {
     @Override
     public int compareTo(OCFile another) {
         if (isFolder() && another.isFolder()) {
-            return getRemotePath().toLowerCase().compareTo(another.getRemotePath().toLowerCase());
+            return getRemotePath().toLowerCase(Locale.ROOT).compareTo(another.getRemotePath().toLowerCase(Locale.ROOT));
         } else if (isFolder()) {
             return -1;
         } else if (another.isFolder()) {

src/main/java/com/owncloud/android/operations/DetectAuthenticationMethodOperation.java

@@ -32,6 +32,7 @@ import com.owncloud.android.lib.resources.files.ExistenceCheckRemoteOperation;
 import org.apache.commons.httpclient.HttpStatus;
 
 import java.util.ArrayList;
+import java.util.Locale;
 
 /**
  * Operation to find out what authentication method requires the server to access files.
@@ -101,7 +102,7 @@ public class DetectAuthenticationMethodOperation extends RemoteOperation {
 
             for (String header : authHeaders) {
                 // currently we only support basic auth
-                if (header.toLowerCase().startsWith("basic")) {
+                if (header.toLowerCase(Locale.ROOT).startsWith("basic")) {
                     authMethod = AuthenticationMethod.BASIC_HTTP_AUTH;
                     break;
                 }

src/main/java/com/owncloud/android/operations/GetServerInfoOperation.java

@@ -34,6 +34,7 @@ import com.owncloud.android.lib.resources.status.OwnCloudVersion;
 import com.owncloud.android.operations.DetectAuthenticationMethodOperation.AuthenticationMethod;
 
 import java.util.ArrayList;
+import java.util.Locale;
 
 /**
  * Get basic information from an ownCloud server given its URL.
@@ -119,7 +120,7 @@ public class GetServerInfoOperation extends RemoteOperation {
             if (trimmedUrl.endsWith("/")) {
                 trimmedUrl = trimmedUrl.substring(0, trimmedUrl.length() - 1);
             }
-            if (trimmedUrl.toLowerCase().endsWith(AuthenticatorUrlUtils.WEBDAV_PATH_4_0_AND_LATER)) {
+            if (trimmedUrl.toLowerCase(Locale.ROOT).endsWith(AuthenticatorUrlUtils.WEBDAV_PATH_4_0_AND_LATER)) {
                 trimmedUrl = trimmedUrl.substring(0,
                         trimmedUrl.length() - AuthenticatorUrlUtils.WEBDAV_PATH_4_0_AND_LATER.length());
             }
@@ -129,8 +130,8 @@ public class GetServerInfoOperation extends RemoteOperation {
 
     
     private String normalizeProtocolPrefix(String url, boolean isSslConn) {
-        if (!url.toLowerCase().startsWith("http://") &&
-                !url.toLowerCase().startsWith("https://")) {
+        if (!url.toLowerCase(Locale.ROOT).startsWith("http://") &&
+                !url.toLowerCase(Locale.ROOT).startsWith("https://")) {
             if (isSslConn) {
                 return "https://" + url;
             } else {

src/main/java/com/owncloud/android/providers/UsersAndGroupsSearchProvider.java

@@ -51,6 +51,7 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Locale;
 
 
 /**
@@ -148,7 +149,7 @@ public class UsersAndGroupsSearchProvider extends ContentProvider {
         MatrixCursor response = null;
 
 
-        String userQuery = uri.getLastPathSegment().toLowerCase();
+        String userQuery = uri.getLastPathSegment().toLowerCase(Locale.ROOT);
 
 
         /// need to trust on the AccountUtils to get the current account since the query in the client side is not

src/main/java/com/owncloud/android/ui/TextDrawable.java

@@ -33,6 +33,7 @@ import com.owncloud.android.utils.BitmapUtils;
 
 import java.io.UnsupportedEncodingException;
 import java.security.NoSuchAlgorithmException;
+import java.util.Locale;
 
 /**
  * A Drawable object that draws text (1 character) on top of a circular/filled background.
@@ -116,7 +117,8 @@ public class TextDrawable extends Drawable {
         int[] hsl = BitmapUtils.calculateHSL(name);
         int[] rgb = BitmapUtils.HSLtoRGB(hsl[0], hsl[1], hsl[2], 1);
 
-        return new TextDrawable(name.substring(0, 1).toUpperCase(), rgb[0], rgb[1], rgb[2], radiusInDp);
+        return new TextDrawable(name.substring(0, 1).toUpperCase(Locale.getDefault()), rgb[0], rgb[1], rgb[2],
+                radiusInDp);
     }
 
     /**

src/main/java/com/owncloud/android/ui/activity/SyncedFoldersActivity.java

@@ -74,6 +74,7 @@ import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 
 import static android.support.design.widget.AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS;
@@ -280,7 +281,8 @@ public class SyncedFoldersActivity extends FileActivity implements SyncedFolderA
                 } else if (f2 == null) {
                     return 1;
                 } else if (f1.isEnabled() && f2.isEnabled()) {
-                    return f1.getFolderName().toLowerCase().compareTo(f2.getFolderName().toLowerCase());
+                    return f1.getFolderName().toLowerCase(Locale.getDefault()).compareTo(
+                            f2.getFolderName().toLowerCase(Locale.getDefault()));
                 } else if (f1.isEnabled()) {
                     return -1;
                 } else if (f2.isEnabled()) {
@@ -291,14 +293,16 @@ public class SyncedFoldersActivity extends FileActivity implements SyncedFolderA
                     return -1;
                 } else if (f2.getFolderName() == null) {
                     return 1;
-                } else if (PRIORITIZED_FOLDER.equals(f1.getFolderName()) && PRIORITIZED_FOLDER.equals(f2.getFolderName())) {
+                } else if (PRIORITIZED_FOLDER.equals(f1.getFolderName()) &&
+                        PRIORITIZED_FOLDER.equals(f2.getFolderName())) {
                     return 0;
                 } else if (PRIORITIZED_FOLDER.equals(f1.getFolderName())) {
                     return -1;
                 } else if (PRIORITIZED_FOLDER.equals(f2.getFolderName())) {
                     return 1;
                 } else {
-                    return f1.getFolderName().toLowerCase().compareTo(f2.getFolderName().toLowerCase());
+                    return f1.getFolderName().toLowerCase(Locale.getDefault()).compareTo(
+                            f2.getFolderName().toLowerCase(Locale.getDefault()));
                 }
             }
         });

src/main/java/com/owncloud/android/ui/adapter/FileListListAdapter.java

@@ -71,6 +71,7 @@ import com.owncloud.android.utils.ThemeUtils;
 
 import java.io.File;
 import java.util.ArrayList;
+import java.util.Locale;
 import java.util.Vector;
 
 
@@ -686,7 +687,8 @@ public class FileListListAdapter extends BaseAdapter {
                 for (int i = 0; i < mFilesAll.size(); i++) {
                     OCFile currentFile = mFilesAll.get(i);
                     if (currentFile.getParentRemotePath().equals(currentDirectory.getRemotePath()) &&
-                            currentFile.getFileName().toLowerCase().contains(constraint.toString().toLowerCase()) &&
+                            currentFile.getFileName().toLowerCase(Locale.getDefault()).contains(
+                                    constraint.toString().toLowerCase(Locale.getDefault())) && 
                             !filteredFiles.contains(currentFile)) {
                         filteredFiles.add(currentFile);
                     }

src/main/java/com/owncloud/android/ui/adapter/LocalFileListAdapter.java

@@ -47,6 +47,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
+import java.util.Locale;
 import java.util.Vector;
 
 /**
@@ -147,12 +148,12 @@ public class LocalFileListAdapter extends BaseAdapter implements FilterableListA
             }
 
             if(!ViewType.GRID_IMAGE.equals(viewType)) {
-                TextView fileName = (TextView) view.findViewById(R.id.Filename);
+                TextView fileName = view.findViewById(R.id.Filename);
                 String name = file.getName();
                 fileName.setText(name);
             }
 
-            ImageView fileIcon = (ImageView) view.findViewById(R.id.thumbnail);
+            ImageView fileIcon = view.findViewById(R.id.thumbnail);
 
             /** Cancellation needs do be checked and done before changing the drawable in fileIcon, or
              * {@link ThumbnailsCacheManager#cancelPotentialThumbnailWork} will NEVER cancel any task.
@@ -166,11 +167,11 @@ public class LocalFileListAdapter extends BaseAdapter implements FilterableListA
             }
             fileIcon.setTag(file.hashCode());
 
-            ImageView checkBoxV = (ImageView) view.findViewById(R.id.custom_checkbox);
-            TextView fileSizeV = (TextView) view.findViewById(R.id.file_size);
-            TextView fileSizeSeparatorV = (TextView) view.findViewById(R.id.file_separator);
+            ImageView checkBoxV = view.findViewById(R.id.custom_checkbox);
+            TextView fileSizeV = view.findViewById(R.id.file_size);
+            TextView fileSizeSeparatorV = view.findViewById(R.id.file_separator);
             if (!isGridView) {
-                TextView lastModV = (TextView) view.findViewById(R.id.last_mod);
+                TextView lastModV = view.findViewById(R.id.last_mod);
                 lastModV.setVisibility(View.VISIBLE);
                 lastModV.setText(DisplayUtils.getRelativeTimestamp(mContext, file.lastModified()));
                 view.findViewById(R.id.overflow_menu).setVisibility(View.GONE);
@@ -289,7 +290,8 @@ public class LocalFileListAdapter extends BaseAdapter implements FilterableListA
                 }
             
                 private int compareNames(File lhs, File rhs) {
-                    return lhs.getName().toLowerCase().compareTo(rhs.getName().toLowerCase());                
+                    return lhs.getName().toLowerCase(Locale.getDefault()).compareTo(
+                            rhs.getName().toLowerCase(Locale.getDefault()));                
                 }
             });
 
@@ -329,9 +331,9 @@ public class LocalFileListAdapter extends BaseAdapter implements FilterableListA
             mFiles = mFilesAll.toArray(new File[1]);
         } else {
             ArrayList<File> result = new ArrayList<>();
-            text = text.toLowerCase();
+            text = text.toLowerCase(Locale.getDefault());
             for (File file: mFilesAll) {
-                if (file.getName().toLowerCase().contains(text)) {
+                if (file.getName().toLowerCase(Locale.getDefault()).contains(text)) {
                     result.add(file);
                 }
             }

src/main/java/com/owncloud/android/ui/dialog/ShareLinkToDialog.java

@@ -48,6 +48,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Locale;
 
 /**
  * Dialog showing a list activities able to resolve a given Intent, 
@@ -92,7 +93,7 @@ public class ShareLinkToDialog  extends DialogFragment {
         ResolveInfo resolveInfo;
         while (it.hasNext()) {
             resolveInfo = it.next();
-            if (packagesToExcludeList.contains(resolveInfo.activityInfo.packageName.toLowerCase())){
+            if (packagesToExcludeList.contains(resolveInfo.activityInfo.packageName.toLowerCase(Locale.ROOT))) {
                 it.remove();
             }
         }
@@ -169,9 +170,9 @@ public class ShareLinkToDialog  extends DialogFragment {
         }
         
         private void bindView(int position, View row) {
-            TextView label = (TextView) row.findViewById(R.id.title);
+            TextView label = row.findViewById(R.id.title);
             label.setText(getItem(position).loadLabel(mPackageManager));
-            ImageView icon = (ImageView) row.findViewById(R.id.icon);
+            ImageView icon = row.findViewById(R.id.icon);
             icon.setImageDrawable(getItem(position).loadIcon(mPackageManager));
         }
     }

src/main/java/com/owncloud/android/utils/BitmapUtils.java

@@ -34,6 +34,7 @@ import org.apache.commons.codec.binary.Hex;
 import java.io.UnsupportedEncodingException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.util.Locale;
 
 /**
  * Utility class with methods for decoding Bitmaps.
@@ -277,7 +278,7 @@ public class BitmapUtils {
         int lum = 68;
         int modulo = 16;
 
-        String hash = name.toLowerCase().replaceAll("[^0-9a-f]", "");
+        String hash = name.toLowerCase(Locale.ROOT).replaceAll("[^0-9a-f]", "");
 
         if (!hash.matches("^[0-9a-f]{32}")) {
             hash = md5(hash);

src/main/java/com/owncloud/android/utils/DisplayUtils.java

@@ -88,6 +88,7 @@ import java.util.Collection;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 
@@ -163,7 +164,7 @@ public class DisplayUtils {
             return mimeType2HumanReadable.get(mimetype);
         }
         if (mimetype.split("/").length >= 2) {
-            return mimetype.split("/")[1].toUpperCase() + " file";
+            return mimetype.split("/")[1].toUpperCase(Locale.getDefault()) + " file";
         }
         return MIME_TYPE_UNKNOWN;
     }

src/main/java/com/owncloud/android/utils/FileStorageUtils.java

@@ -286,7 +286,7 @@ public class FileStorageUtils {
         if (pos >= 0) {
             extension = path.substring(pos + 1);
         }
-        String result = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension.toLowerCase());
+        String result = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension.toLowerCase(Locale.ROOT));
         return (result != null) ? result : "";
     }
 

src/main/java/com/owncloud/android/utils/MimeTypeUtil.java

@@ -33,6 +33,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 
 /**
@@ -177,29 +178,29 @@ public class MimeTypeUtil {
      * @return 'True' if the mime type defines image
      */
     public static boolean isImage(String mimeType) {
-        return (mimeType != null && mimeType.toLowerCase().startsWith("image/") && !mimeType.toLowerCase().contains
-                ("djvu"));
+        return (mimeType != null && mimeType.toLowerCase(Locale.ROOT).startsWith("image/") &&
+                !mimeType.toLowerCase(Locale.ROOT).contains("djvu"));
     }
 
     /**
      * @return 'True' the mime type defines video
      */
     public static boolean isVideo(String mimeType) {
-        return (mimeType != null && mimeType.toLowerCase().startsWith("video/"));
+        return (mimeType != null && mimeType.toLowerCase(Locale.ROOT).startsWith("video/"));
     }
 
     /**
      * @return 'True' the mime type defines audio
      */
     public static boolean isAudio(String mimeType) {
-        return (mimeType != null && mimeType.toLowerCase().startsWith("audio/"));
+        return (mimeType != null && mimeType.toLowerCase(Locale.ROOT).startsWith("audio/"));
     }
 
     /**
      * @return 'True' if mime type defines text
      */
     public static boolean isText(String mimeType) {
-        return (mimeType != null && mimeType.toLowerCase().startsWith("text/"));
+        return (mimeType != null && mimeType.toLowerCase(Locale.ROOT).startsWith("text/"));
     }
 
     /**
@@ -284,7 +285,7 @@ public class MimeTypeUtil {
      */
     private static String extractMimeType(File file) {
         Uri selectedUri = Uri.fromFile(file);
-        String fileExtension = MimeTypeMap.getFileExtensionFromUrl(selectedUri.toString().toLowerCase());
+        String fileExtension = MimeTypeMap.getFileExtensionFromUrl(selectedUri.toString().toLowerCase(Locale.ROOT));
         return MimeTypeMap.getSingleton().getMimeTypeFromExtension(fileExtension);
     }
 
@@ -354,7 +355,7 @@ public class MimeTypeUtil {
         if (pos >= 0) {
             extension = path.substring(pos + 1);
         }
-        String result = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension.toLowerCase());
+        String result = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension.toLowerCase(Locale.ROOT));
         return (result != null) ? result : "";
     }
 
@@ -365,7 +366,7 @@ public class MimeTypeUtil {
      * @return the file extension
      */
     private static String getExtension(String filename) {
-        return filename.substring(filename.lastIndexOf('.') + 1).toLowerCase();
+        return filename.substring(filename.lastIndexOf('.') + 1).toLowerCase(Locale.ROOT);
     }
 
     /**

src/main/java/third_parties/daveKoeller/AlphanumComparator.java

@@ -29,6 +29,7 @@ import com.owncloud.android.datamodel.OCFile;
 import java.io.File;
 import java.text.Collator;
 import java.util.Comparator;
+import java.util.Locale;
 
 /*
  * This is an updated version with enhancements made by Daniel Migowski, Andre Bogus, and David Koelle
@@ -86,15 +87,15 @@ public class AlphanumComparator<T> implements Comparator<T> {
     }
 
     public int compare(OCFile o1, OCFile o2) {
-        String s1 = o1.getRemotePath().toLowerCase();
-        String s2 = o2.getRemotePath().toLowerCase();
+        String s1 = o1.getRemotePath().toLowerCase(Locale.ROOT);
+        String s2 = o2.getRemotePath().toLowerCase(Locale.ROOT);
 
         return compare(s1, s2);
     }
 
     public int compare(File f1, File f2) {
-        String s1 = f1.getPath().toLowerCase();
-        String s2 = f2.getPath().toLowerCase();
+        String s1 = f1.getPath().toLowerCase(Locale.ROOT);
+        String s2 = f2.getPath().toLowerCase(Locale.ROOT);
 
         return compare(s1, s2);
     }

src/main/java/third_parties/ezvcard_android/DataMappings.java

@@ -4,6 +4,7 @@ import android.provider.ContactsContract;
 
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 
 import ezvcard.parameter.AddressType;
@@ -164,7 +165,7 @@ public class DataMappings {
             return ContactsContract.CommonDataKinds.Website.TYPE_CUSTOM;
         }
 
-        type = type.toLowerCase();
+        type = type.toLowerCase(Locale.ROOT);
         Integer value = websiteTypeMappings.get(type);
         return (value == null) ? ContactsContract.CommonDataKinds.Website.TYPE_CUSTOM : value;
     }
@@ -180,7 +181,7 @@ public class DataMappings {
             return ContactsContract.CommonDataKinds.Event.TYPE_OTHER;
         }
 
-        type = type.toLowerCase();
+        type = type.toLowerCase(Locale.ROOT);
         for (Map.Entry<String, Integer> entry : abDateMappings.entrySet()){
             if (type.contains(entry.getKey())){
                 return entry.getValue();
@@ -200,7 +201,7 @@ public class DataMappings {
             return ContactsContract.CommonDataKinds.Relation.TYPE_CUSTOM;
         }
 
-        type = type.toLowerCase();
+        type = type.toLowerCase(Locale.ROOT);
         for (Map.Entry<String, Integer> entry : abRelatedNamesMappings.entrySet()){
             if (type.contains(entry.getKey())){
                 return entry.getValue();
@@ -230,7 +231,7 @@ public class DataMappings {
             return ContactsContract.CommonDataKinds.Im.PROTOCOL_CUSTOM;
         }
 
-        protocol = protocol.toLowerCase();
+        protocol = protocol.toLowerCase(Locale.ROOT);
         Integer value = imProtocolMappings.get(protocol);
         return (value == null) ? ContactsContract.CommonDataKinds.Im.PROTOCOL_CUSTOM : value;
     }

src/modified/java/com/owncloud/android/utils/PushUtils.java

@@ -63,6 +63,7 @@ import java.security.PublicKey;
 import java.security.spec.InvalidKeySpecException;
 import java.security.spec.PKCS8EncodedKeySpec;
 import java.security.spec.X509EncodedKeySpec;
+import java.util.Locale;
 
 public class PushUtils {
 
@@ -191,7 +192,7 @@ public class PushUtils {
         if (!TextUtils.isEmpty(MainApp.getAppContext().getResources().getString(R.string.push_server_url)) &&
                 !TextUtils.isEmpty(token)) {
             PushUtils.generateRsa2048KeyPair();
-            String pushTokenHash = PushUtils.generateSHA512Hash(token).toLowerCase();
+            String pushTokenHash = PushUtils.generateSHA512Hash(token).toLowerCase(Locale.ROOT);
             PublicKey devicePublicKey = (PublicKey) PushUtils.readKeyFromFile(true);
             if (devicePublicKey != null) {
                 byte[] publicKeyBytes = Base64.encode(devicePublicKey.getEncoded(), Base64.NO_WRAP);