Stackoverflow exception if resource has self referencing linkage (of any type, like Satisfaction)

[broehl-ptc]

Hi all,

we have an Stackoverflow exception encountered as soon as the user had configured a linkage for a requirement resource, to self reference.

With our application, we are able to read the resource without problems, but when comes down to send an updated version of that resource to the server back, the serialization via Eclipse Lyo fails badly.

The stacktrace is attached below, happend with version Eclipse Lyo 5.1.1.Final.

stackoverflow.put.resource.txt

[berezovskyi]

Hallo Benjamin,

Thank you for the bug report! Quite an unfortunate bug. We already have loop detecting via the visitedResources map but I think you either hit an issue when one of the branches is not covered by the loop detection guard or it's a problem with blank nodes - I see in the stacktrace that handleLocalResource is hit repeatedly.

I looked at the code very briefly and cannot find the problem as reported. Mainly because on the 5.1.1.Final tag, the JenaModelHelper lines do not match the stack trace at all. My current working theory is that this branch

lyo/core/oslc4j-core/src/main/java/org/eclipse/lyo/oslc4j/provider/jena/JenaModelHelper.java

Lines 1643 to 1658 in 91e00cc

	else if (value.getClass().getAnnotation(OslcResourceShape.class) != null || value instanceof URI)
	{
	//TODO: Until we handle XMLLiteral for incoming unknown resources, need to assume it is
	// not XMLLiteral
	boolean xmlliteral = false;
	handleLocalResource(objectClass,
	null,
	xmlliteral,
	value,
	model,
	resource,
	property,
	nestedProperties,
	onlyNested,
	null);
	}

is missing the !visitedResources.containsKey check.

If you find and verify a fix, I would appreciate a pull request. Unfortunately, I am quite busy the next few weeks ahead to spend more time on this.

Viele Grüße aus Stockholm
Andrew

[broehl-ptc]

Hello Andrew,

that sounds promising.

Yes, the stacktrace line numbers do not match, since we introduced a patch, adding 6 lines at line 1192.

I will try to create a PR, according to the existing implementation with visitedResources :)

[Jad-el-khoury]

@broehl-ptc Could you possibily update to the latest Lyo 7? Quite a lot has happened since 5.