Regression in v2 when the last step in the selector has a predicate index

[cjmamo]

Describe the bug

Quoting the conversation in https://groups.google.com/g/smooks-user/c/hLen9nplpMo/m/8gmWQmpKAQAJ:

Unfortunately, we hit another problem. When the smooks config contains an xpath expression with positions declarations a java.util.ConcurrentModificationException will be thrown. We could reproduce the problem with a modified version of the xml2java example.

The smooks config <jb:bean beanId="header" class="org.smooks.examples.xml2java.model.Header" createOnElement="header[2]">

This will produce a

org.smooks.api.SmooksException: Failed to filter source

            at org.smooks.engine.delivery.sax.ng.SaxNgFilter.doFilter(SaxNgFilter.java:122)

            at org.smooks.engine.delivery.sax.ng.SaxNgFilter.doFilter(SaxNgFilter.java:94)

            at org.smooks.Smooks._filter(Smooks.java:546)

            at org.smooks.Smooks.filterSource(Smooks.java:499)

            at org.smooks.examples.xml2java.Main.runSmooks(Main.java:85)

            at org.smooks.examples.xml2java.JavabeanTest.test(JavabeanTest.java:62)

            at java.base/java.lang.reflect.Method.invoke(Method.java:568)

            at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

            at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

Caused by: java.util.ConcurrentModificationException

            at java.base/java.util.ArrayList$Itr.checkForComodification(ArrayList.java:1013)

            at java.base/java.util.ArrayList$Itr.next(ArrayList.java:967)

            at org.smooks.engine.delivery.sax.ng.SaxNgContentDeliveryConfig.addPositionCounters(SaxNgContentDeliveryConfig.java:243)

            at org.smooks.engine.delivery.sax.ng.SaxNgContentDeliveryConfig.addPositionCounters(SaxNgContentDeliveryConfig.java:232)

            at org.smooks.engine.delivery.sax.ng.SaxNgContentDeliveryConfig.reduceIndex(SaxNgContentDeliveryConfig.java:222)

            at org.smooks.engine.delivery.sax.ng.SaxNgContentDeliveryConfig.get(SaxNgContentDeliveryConfig.java:151)

            at org.smooks.engine.delivery.sax.ng.SaxNgHandler.<init>(SaxNgHandler.java:118)

            at org.smooks.engine.delivery.sax.ng.SaxNgHandler.<init>(SaxNgHandler.java:105)

            at org.smooks.engine.delivery.sax.ng.SaxNgParser.parse(SaxNgParser.java:71)

            at org.smooks.engine.delivery.sax.ng.SaxNgFilter.doFilter(SaxNgFilter.java:110)

            ... 8 more

The complete smooks config looks like this:

<jb:bean beanId="order" class="org.smooks.examples.xml2java.model.Order" createOnElement="order">

    <jb:wiring property="header" beanIdRef="header" />

    <jb:wiring property="orderItems" beanIdRef="orderItems" />

</jb:bean>



<jb:bean beanId="orderItems" class="java.util.ArrayList" createOnElement="order">

    <jb:wiring beanIdRef="orderItem" />

</jb:bean>

<jb:bean beanId="header" class="org.smooks.examples.xml2java.model.Header" createOnElement="header[2]">

    <jb:value property="date" decoder="Date" data="header/date">

        <jb:decodeParam name="format">EEE MMM dd HH:mm:ss z yyyy</jb:decodeParam>

        <jb:decodeParam name="locale-language">en</jb:decodeParam>

        <jb:decodeParam name="locale-country">IE</jb:decodeParam>

    </jb:value>

    <jb:value property="customerNumber" decoder="Long" data="header/customer/@number" />

    <jb:value property="customerName" data="header/customer" />

</jb:bean>



<jb:bean beanId="orderItem" class="org.smooks.examples.xml2java.model.OrderItem" createOnElement="order-item">

    <jb:value property="productId" decoder="Long" data="order-item/product" />

    <jb:value property="quantity" decoder="Integer" data="order-item/quantity" />

    <jb:value property="price" decoder="Double" data="order-item/price" />

</jb:bean>

To Reproduce

Use a selector where the last step has a predicate index like header[2].

Expected behavior

No exception should occur.

Environment

• Smooks: 2.0.0-RC3