[SLING-7685] data-sly-resource throws RecursionTooDeepException when used with dynamic variables that are null / empty

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Scripting HTL Engine 1.0.54-1.4.0, Scripting HTL Testing Content 1.0.10-1.4.0, Scripting HTL Testing 1.0.10-1.4.0
• Component/s: Scripting
• Assignee: Radu Cotescu
• Reporter: Sagar Sane
• Created: 27/May/18 00:42
• Updated: 22/Jun/18 14:12
• Resolved: 18/Jun/18 15:54

Description

I am on AEM 6.3.1.2.

If I use data-sly-resource w/ dynamic variable which is null or empty, I get a RecursionTooDeepException runtime. The stack looks something like this (redacting project specific stuff): 

2018-05-26 20:18:33,335 *ERROR* [0:0:0:0:0:0:0:1 [1527380309473] GET /content/<path> HTTP/1.1] org.apache.sling.engine.impl.SlingRequestProcessorImpl service: Uncaught SlingException
org.apache.sling.scripting.sightly.SightlyException: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.SlingException: Cannot get DefaultSlingScript: org.apache.sling.api.request.RecursionTooDeepException: /content/<path>
at com.adobe.cq.sightly.WCMScriptHelper.includeScript(WCMScriptHelper.java:227)
at com.adobe.cq.sightly.internal.extensions.IncludeExtension.call(IncludeExtension.java:73)
at org.apache.sling.scripting.sightly.impl.engine.runtime.RenderContextImpl.call(RenderContextImpl.java:69)
at  org.apache.sling.scripting.sightly.java.compiler.RenderUnit.render(RenderUnit.java:48)
at org.apache.sling.scripting.sightly.impl.engine.SightlyCompiledScript.eval(SightlyCompiledScript.java:61)
at org.apache.sling.scripting.core.impl.DefaultSlingScript.call(DefaultSlingScript.java:386)
at org.apache.sling.scripting.core.impl.DefaultSlingScript.eval(DefaultSlingScript.java:184)
at org.apache.sling.scripting.core.impl.DefaultSlingScript.service(DefaultSlingScript.java:491)
at org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:552)
at org.apache.sling.engine.impl.filter.SlingComponentFilterChain.render(SlingComponentFilterChain.java:44)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:77)
at com.adobe.acs.commons.wcm.impl.ComponentErrorHandlerImpl.doFilter(ComponentErrorHandlerImpl.java:217)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:68)
at com.day.cq.wcm.core.impl.WCMDebugFilter.doFilterWithErrorHandling(WCMDebugFilter.java:192)
at com.day.cq.wcm.core.impl.WCMDebugFilter.doFilter(WCMDebugFilter.java:159)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:68)
at org.apache.sling.dynamicinclude.IncludeTagFilter.doFilter(IncludeTagFilter.java:71)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:68)
at com.day.cq.wcm.core.impl.WCMDeveloperModeFilter.doFilter(WCMDeveloperModeFilter.java:119)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:68)
at com.day.cq.wcm.core.impl.WCMComponentFilter.doFilter(WCMComponentFilter.java:278)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:68)
at  org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:68)
at com.day.cq.personalization.impl.TargetComponentFilter.doFilter(TargetComponentFilter.java:96)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:68)
at org.apache.sling.engine.impl.SlingRequestProcessorImpl.processComponent(SlingRequestProcessorImpl.java:282)
at org.apache.sling.engine.impl.SlingRequestProcessorImpl.dispatchRequest(SlingRequestProcessorImpl.java:322)
at org.apache.sling.engine.impl.request.SlingRequestDispatcher.dispatch(SlingRequestDispatcher.java:211)
at org.apache.sling.engine.impl.request.SlingRequestDispatcher.include(SlingRequestDispatcher.java:104)
at com.day.cq.wcm.core.impl.WCMComponentFilter$ForwardRequestDispatcher.include(WCMComponentFilter.java:516)
at org.apache.jsp.libs.cq.Page.Page_jsp._jspService(Page_jsp.java:106)
at org.apache.sling.scripting.jsp.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)

It seems like the resource include implementation is scanning the page's whole resource tree. I think the behavior is similar to what's mentioned in the thread here

I can get around this by putting a data-sly-test in the same sly tag as the data-sly-resource tag. 

(This is a follow up on discussion here)

A simple way to reproduce this is to have a Sling Model like : 

package com.sling7685;

import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.models.annotations.DefaultInjectionStrategy;
import org.apache.sling.models.annotations.Model;

@Model(adaptables = {SlingHttpServletRequest.class, Resource.class},
        defaultInjectionStrategy = DefaultInjectionStrategy.OPTIONAL)
public class ReproduceSling7685 {

    private String testVariable;


    public String getTestVariable() {
        return testVariable;
    }
}

Then the HTL script could be something like :

<sly data-sly-use.model="com.sling7685.ReproduceSling7685"></sly>
<sly data-sly-resource="${model.testVariable @ wcmmode='disabled'}"></sly>

Please let me know if I should add any more details. 

Thanks!