create namespace validator

src/main/java/com/reandroid/lib/apk/ApkModuleXmlDecoder.java

@@ -17,6 +17,7 @@ package com.reandroid.lib.apk;
 
 import com.reandroid.archive.InputSource;
 import com.reandroid.lib.apk.xmldecoder.XMLBagDecoder;
+import com.reandroid.lib.apk.xmldecoder.XMLNamespaceValidator;
 import com.reandroid.lib.arsc.chunk.PackageBlock;
 import com.reandroid.lib.arsc.chunk.TableBlock;
 import com.reandroid.lib.arsc.chunk.TypeBlock;
@@ -117,6 +118,8 @@ import java.util.*;
         File file=new File(resDir, path);
 
         logVerbose("Decoding: "+path);
+        XMLNamespaceValidator namespaceValidator=new XMLNamespaceValidator(resXmlBlock);
+        namespaceValidator.validate();
         XMLDocument xmlDocument=resXmlBlock.decodeToXml(entryStore, packageBlock.getId());
         xmlDocument.save(file, true);
 

src/main/java/com/reandroid/lib/apk/xmldecoder/XMLNamespaceValidator.java

@@ -0,0 +1,139 @@
+ /*
+  *  Copyright (C) 2022 github.com/REAndroid
+  *
+  *  Licensed under the Apache License, Version 2.0 (the "License");
+  *  you may not use this file except in compliance with the License.
+  *  You may obtain a copy of the License at
+  *
+  *      http://www.apache.org/licenses/LICENSE-2.0
+  *
+  * Unless required by applicable law or agreed to in writing, software
+  * distributed under the License is distributed on an "AS IS" BASIS,
+  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  * See the License for the specific language governing permissions and
+  * limitations under the License.
+  */
+package com.reandroid.lib.apk.xmldecoder;
+
+import com.reandroid.lib.arsc.chunk.xml.*;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class XMLNamespaceValidator {
+    private static final String URI_ANDROID="http://schemas.android.com/apk/res/android";
+    private static final String URI_APP="http://schemas.android.com/apk/res-auto";
+    private static final String PREFIX_ANDROID ="android";
+    private static final String PREFIX_APP="app";
+    private final ResXmlBlock xmlBlock;
+    private List<ResXmlAttribute> mAttributeList;
+    private ResXmlElement mRootElement;
+    private ResXmlStartNamespace mNsAndroid;
+    private ResXmlStartNamespace mNsApp;
+    public XMLNamespaceValidator(ResXmlBlock xmlBlock){
+        this.xmlBlock=xmlBlock;
+    }
+    public void validate(){
+        if(getRootElement()==null){
+            return;
+        }
+        for(ResXmlAttribute attribute:getAttributes()){
+            validate(attribute);
+        }
+    }
+    private void validate(ResXmlAttribute attribute){
+        int resourceId=attribute.getNameResourceID();
+        if(resourceId==0){
+            return;
+        }
+        int pkgId=toPackageId(resourceId);
+        if(isAndroid(pkgId)){
+            setAndroidNamespace(attribute);
+        }else {
+            setAppNamespace(attribute);
+        }
+    }
+    private void setAppNamespace(ResXmlAttribute attribute){
+        if(isValidAppNamespace(attribute)){
+            return;
+        }
+        ResXmlStartNamespace ns = getOrCreateApp();
+        attribute.setNamespaceReference(ns.getUriReference());
+    }
+    private boolean isValidAppNamespace(ResXmlAttribute attribute){
+        String uri = attribute.getUri();
+        String prefix = attribute.getNamePrefix();
+        if(URI_ANDROID.equals(uri) || PREFIX_ANDROID.equals(prefix)){
+            return false;
+        }
+        if(isEmpty(uri) || isEmpty(prefix)){
+            return false;
+        }
+        return true;
+    }
+    private void setAndroidNamespace(ResXmlAttribute attribute){
+        if(URI_ANDROID.equals(attribute.getUri())
+                && PREFIX_ANDROID.equals(attribute.getNamePrefix())){
+            return;
+        }
+        ResXmlStartNamespace ns = getOrCreateAndroid();
+        attribute.setNamespaceReference(ns.getUriReference());
+    }
+    private ResXmlStartNamespace getOrCreateApp(){
+        if(mNsApp !=null){
+            return mNsApp;
+        }
+        ResXmlElement root=getRootElement();
+        ResXmlStartNamespace ns = root.getOrCreateNamespace(URI_APP, PREFIX_APP);
+        String prefix=ns.getPrefix();
+        if(PREFIX_ANDROID.equals(prefix) || isEmpty(prefix)){
+            ns.setPrefix(PREFIX_APP);
+        }
+        mNsApp = ns;
+        return mNsApp;
+    }
+    private ResXmlStartNamespace getOrCreateAndroid(){
+        if(mNsAndroid !=null){
+            return mNsAndroid;
+        }
+        ResXmlElement root=getRootElement();
+        ResXmlStartNamespace ns = root.getOrCreateNamespace(URI_ANDROID, PREFIX_ANDROID);
+        if(!PREFIX_ANDROID.equals(ns.getPrefix())){
+            ns.setPrefix(PREFIX_ANDROID);
+        }
+        mNsAndroid =ns;
+        return mNsAndroid;
+    }
+    private ResXmlElement getRootElement() {
+        if(mRootElement==null){
+            mRootElement = xmlBlock.getResXmlElement();
+        }
+        return mRootElement;
+    }
+    private List<ResXmlAttribute> getAttributes(){
+        if(mAttributeList==null){
+            mAttributeList=listAttributes(xmlBlock.getResXmlElement());
+        }
+        return mAttributeList;
+    }
+    private List<ResXmlAttribute> listAttributes(ResXmlElement element){
+        List<ResXmlAttribute> results = new ArrayList<>(element.listAttributes());
+        for(ResXmlElement child:element.listElements()){
+            results.addAll(listAttributes(child));
+        }
+        return results;
+    }
+    private boolean isAndroid(int pkgId){
+        return pkgId==1;
+    }
+    private int toPackageId(int resId){
+        return (resId >> 24 & 0xFF);
+    }
+    private static boolean isEmpty(String str){
+        if(str==null){
+            return true;
+        }
+        str=str.trim();
+        return str.length()==0;
+    }
+}