Fix compatibility issues in XmlPullParserFactory.

- We should set features on a parser only if the feature
  value is true. I.e, we guarantee that we'll never call
  XmlPullParser.setFeature(..., false).

- In change 0363556bad8930a, we didn't consider the fact
  that apps could extend XmlPullParserFactory and modify
  protected fields to change the parser / serializer that's
  instantiated. I've reinstated this feature, despite the
  fact that it's a particularly pointless feature on a
  more-or-less pointless public API. Apps can and should
  instantiate their own parser instances directly instead
  of going through this factory.

bug: 12956724

Change-Id: I793eba335b5385eb641e023b3613bba4515a85bf

1 files changed, 341 insertions, 1 deletions

diff --git a/luni/src/test/java/libcore/xml/XmlPullParserFactoryTest.java b/luni/src/test/java/libcore/xml/XmlPullParserFactoryTest.java
index ea795f8..7194414 100644
--- a/luni/src/test/java/libcore/xml/XmlPullParserFactoryTest.java
+++ b/luni/src/test/java/libcore/xml/XmlPullParserFactoryTest.java
@@ -16,19 +16,359 @@
 
 package libcore.xml;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.Reader;
+import java.io.Writer;
 import junit.framework.TestCase;
+import org.kxml2.io.KXmlParser;
+import org.kxml2.io.KXmlSerializer;
 import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlPullParserException;
 import org.xmlpull.v1.XmlPullParserFactory;
 import org.xmlpull.v1.XmlSerializer;
 
 public class XmlPullParserFactoryTest extends TestCase {
 
-    public void testNewInstance() throws Exception {
+    public void testDefaultNewInstance() throws Exception {
         XmlPullParserFactory factory = XmlPullParserFactory.newInstance(null, null);
         XmlPullParser parser = factory.newPullParser();
         XmlSerializer serializer = factory.newSerializer();
 
         assertNotNull(parser);
         assertNotNull(serializer);
+        assertTrue(parser instanceof KXmlParser);
+        assertTrue(serializer instanceof KXmlSerializer);
+    }
+
+    /**
+     * Tests that trying to instantiate a parser with an empty list of
+     * parsers and serializers fails.
+     */
+    public void testOverriding_emptyClassList() {
+        TestXmlPullParserFactory tf = new TestXmlPullParserFactory(null, null);
+
+        try {
+            tf.newPullParser();
+            fail();
+        } catch (XmlPullParserException expected) {
+        }
+
+        try {
+            tf.newPullParser();
+            fail();
+        } catch (XmlPullParserException expected) {
+        }
+    }
+
+    public void testOverriding_customClassList() throws Exception {
+        TestXmlPullParserFactory tf = new TestXmlPullParserFactory(
+                new String[] { "libcore.xml.XmlPullParserFactoryTest$XmlPullParserStub" },
+                new String[] { "libcore.xml.XmlPullParserFactoryTest$XmlSerializerStub" });
+
+        assertTrue(tf.newPullParser() instanceof XmlPullParserStub);
+        assertTrue(tf.newSerializer() instanceof XmlSerializerStub);
+
+        // Also check that we ignore instantiation errors as long as
+        // at least one parser / serializer is instantiable.
+        tf = new TestXmlPullParserFactory(
+                new String[] {
+                        "libcore.xml.XmlPullParserFactoryTest$InaccessibleXmlParser",
+                        "libcore.xml.XmlPullParserFactoryTest$XmlPullParserStub" },
+                new String[] {
+                        "libcore.xml.XmlPullParserFactoryTest$InaccessibleXmlSerializer",
+                        "libcore.xml.XmlPullParserFactoryTest$XmlSerializerStub" });
+
+        assertTrue(tf.newPullParser() instanceof XmlPullParserStub);
+        assertTrue(tf.newSerializer() instanceof XmlSerializerStub);
+    }
+
+    // https://b/12956724
+    public void testSetFeature_setsFeatureOnlyIfTrue() throws Exception {
+        TestXmlPullParserFactory tf = new TestXmlPullParserFactory(
+                new String[] { "libcore.xml.XmlPullParserFactoryTest$XmlParserThatHatesAllFeatures" }, null);
+
+        tf.setFeature("foo", false);
+        tf.newPullParser();
+    }
+
+
+    /**
+     * A class that makes use of inherited XmlPullParserFactory fields to check they are
+     * supported.
+     */
+    static final class TestXmlPullParserFactory extends XmlPullParserFactory {
+        TestXmlPullParserFactory(String[] parserClassList, String[] serializerClassList) {
+            super();
+            parserClasses.remove(0);
+            serializerClasses.remove(0);
+
+            try {
+                if (parserClassList != null) {
+                    for (String parserClass : parserClassList) {
+                        parserClasses.add(Class.forName(parserClass));
+                    }
+                }
+
+                if (serializerClassList != null) {
+                    for (String serializerClass : serializerClassList) {
+                        serializerClasses.add(Class.forName(serializerClass));
+                    }
+                }
+            } catch (ClassNotFoundException ignored) {
+                throw new AssertionError(ignored);
+            }
+        }
+    }
+
+    public static final class XmlParserThatHatesAllFeatures extends XmlPullParserStub {
+        @Override
+        public void setFeature(String name, boolean state) {
+            fail();
+        }
+    }
+
+    static final class InaccessibleXmlSerializer extends XmlSerializerStub {
+    }
+
+    static final class InaccessibleXmlParser extends XmlPullParserStub {
+    }
+
+    public static class XmlSerializerStub implements XmlSerializer {
+
+        public void setFeature(String name, boolean state) throws IllegalArgumentException,
+                IllegalStateException {
+        }
+
+        public boolean getFeature(String name) {
+            return false;
+        }
+
+        public void setProperty(String name, Object value) {
+        }
+
+        public Object getProperty(String name) {
+            return null;
+        }
+
+        public void setOutput(OutputStream os, String encoding) throws IOException {
+        }
+
+        public void setOutput(Writer writer) throws IOException {
+        }
+
+        public void startDocument(String encoding, Boolean standalone) throws IOException {
+        }
+
+        public void endDocument() throws IOException {
+        }
+
+        public void setPrefix(String prefix, String namespace) throws IOException {
+        }
+
+        public String getPrefix(String namespace, boolean generatePrefix) throws IllegalArgumentException {
+            return null;
+        }
+
+        public int getDepth() {
+            return 0;
+        }
+
+        public String getNamespace() {
+            return null;
+        }
+
+        public String getName() {
+            return null;
+        }
+
+        public XmlSerializer startTag(String namespace, String name) throws IOException {
+            return null;
+        }
+
+        public XmlSerializer attribute(String namespace, String name, String value) throws IOException {
+            return null;
+        }
+
+        public XmlSerializer endTag(String namespace, String name) throws IOException {
+            return null;
+        }
+
+        public XmlSerializer text(String text) throws IOException {
+            return null;
+        }
+
+        public XmlSerializer text(char[] buf, int start, int len) throws IOException {
+            return null;
+        }
+
+        public void cdsect(String text) throws IOException {
+        }
+
+        public void entityRef(String text) throws IOException {
+        }
+
+        public void processingInstruction(String text) throws IOException {
+        }
+
+        public void comment(String text) throws IOException {
+        }
+
+        public void docdecl(String text) throws IOException {
+        }
+
+        public void ignorableWhitespace(String text) throws IOException {
+        }
+
+        public void flush() throws IOException {
+        }
+    }
+
+    public static class XmlPullParserStub implements XmlPullParser {
+        public void setFeature(String name, boolean state) throws XmlPullParserException {
+        }
+
+        public boolean getFeature(String name) {
+            return false;
+        }
+
+        public void setProperty(String name, Object value) throws XmlPullParserException {
+        }
+
+        public Object getProperty(String name) {
+            return null;
+        }
+
+        public void setInput(Reader in) throws XmlPullParserException {
+        }
+
+        public void setInput(InputStream inputStream, String inputEncoding)
+                throws XmlPullParserException {
+        }
+
+        public String getInputEncoding() {
+            return null;
+        }
+
+        public void defineEntityReplacementText(String entityName, String replacementText)
+                throws XmlPullParserException {
+        }
+
+        public int getNamespaceCount(int depth) throws XmlPullParserException {
+            return 0;
+        }
+
+        public String getNamespacePrefix(int pos) throws XmlPullParserException {
+            return null;
+        }
+
+        public String getNamespaceUri(int pos) throws XmlPullParserException {
+            return null;
+        }
+
+        public String getNamespace(String prefix) {
+            return null;
+        }
+
+        public int getDepth() {
+            return 0;
+        }
+
+        public String getPositionDescription() {
+            return null;
+        }
+
+        public int getLineNumber() {
+            return 0;
+        }
+
+        public int getColumnNumber() {
+            return 0;
+        }
+
+        public boolean isWhitespace() throws XmlPullParserException {
+            return false;
+        }
+
+        public String getText() {
+            return null;
+        }
+
+        public char[] getTextCharacters(int[] holderForStartAndLength) {
+            return null;
+        }
+
+        public String getNamespace() {
+            return null;
+        }
+
+        public String getName() {
+            return null;
+        }
+
+        public String getPrefix() {
+            return null;
+        }
+
+        public boolean isEmptyElementTag() throws XmlPullParserException {
+            return false;
+        }
+
+        public int getAttributeCount() {
+            return 0;
+        }
+
+        public String getAttributeNamespace(int index) {
+            return null;
+        }
+
+        public String getAttributeName(int index) {
+            return null;
+        }
+
+        public String getAttributePrefix(int index) {
+            return null;
+        }
+
+        public String getAttributeType(int index) {
+            return null;
+        }
+
+        public boolean isAttributeDefault(int index) {
+            return false;
+        }
+
+        public String getAttributeValue(int index) {
+            return null;
+        }
+
+        public String getAttributeValue(String namespace, String name) {
+            return null;
+        }
+
+        public int getEventType() throws XmlPullParserException {
+            return 0;
+        }
+
+        public int next() throws XmlPullParserException, IOException {
+            return 0;
+        }
+
+        public int nextToken() throws XmlPullParserException, IOException {
+            return 0;
+        }
+
+        public void require(int type, String namespace, String name)
+                throws XmlPullParserException, IOException {
+        }
+
+        public String nextText() throws XmlPullParserException, IOException {
+            return null;
+        }
+
+        public int nextTag() throws XmlPullParserException, IOException {
+            return 0;
+        }
     }
 }