The JCTree.pos may contain incorrect offset for BinaryTrees in some cases. For example, for expression "o != null && o instanceof String", the JCTree.pos for tree corresponding to the "&&" operator points to the beginning of the "instanceof" operator, while is should point to the beginning of the "&&" operator. Tested on revision "1:e4dae1993f8b" cloned from http://hg.openjdk.java.net/jdk7/jdk7/langtools

Test case:

/*
 * @test @(#)T9999999.java
 * @bug 9999999
 * @summary
 */

import com.sun.source.tree.BinaryTree;
import com.sun.source.tree.ClassTree;
import com.sun.source.tree.CompilationUnitTree;
import com.sun.source.tree.MethodTree;
import com.sun.source.tree.VariableTree;
import com.sun.tools.javac.api.JavacTaskImpl;
import com.sun.tools.javac.tree.JCTree;
import java.net.URI;
import java.util.Arrays;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.SimpleJavaFileObject;
import javax.tools.ToolProvider;

public class T9999999 {
    
    public static void main(String[] args) throws Exception {
        final String bootPath = System.getProperty("sun.boot.class.path"); //NOI18N
        final JavaCompiler tool = ToolProvider.getSystemJavaCompiler();
        assert tool != null;

        String code = "package test; public class Test {private void test() {Object o = null; boolean b = o != null && o instanceof String;} private Test() {}}";

        JavacTaskImpl ct = (JavacTaskImpl) tool.getTask(null, null, null, Arrays.asList("-bootclasspath", bootPath, "-Xjcov"), null, Arrays.asList(new MyFileObject(code)));
        CompilationUnitTree cut = ct.parse().iterator().next();
        ClassTree clazz = (ClassTree) cut.getTypeDecls().get(0);
        MethodTree method = (MethodTree) clazz.getMembers().get(0);
        VariableTree condSt = (VariableTree) method.getBody().getStatements().get(1);
        BinaryTree cond = (BinaryTree) condSt.getInitializer();
        JCTree condJC = (JCTree) cond;

        if (condJC.pos != 93)
            throw new IllegalStateException("Unexpected position=" + condJC.pos);
    }
    
    static class MyFileObject extends SimpleJavaFileObject {
        private String text;
        public MyFileObject(String text) {
            super(URI.create("myfo:/Test.java"), JavaFileObject.Kind.SOURCE);
            this.text = text;
        }
        @Override
        public CharSequence getCharContent(boolean ignoreEncodingErrors) {
            return text;
        }
    }
}