In BZ 520211, s3lvatico@gmail.com reported:

What steps will reproduce the problem?
1. While working on a maven project, define a composite jsf component in another maven project (inside the same workspace)
2. While authoring a new jsf (xhtml) page, use the newly created component
3. Activate the code completion feature (CTRL-space) inside the component's tag OR in any other jsf tag.

+ jboss tools 4.4.4

-- Error Details --
Date: Wed Jul 26 15:08:46 CEST 2017
Message: Unhandled event loop exception
Severity: Error
Product: Eclipse 4.6.3.20170314-1500 (org.eclipse.epp.package.jee.product)
Plugin: org.eclipse.ui
Session Data:
eclipse.buildId=4.6.3.M20170301-0400
java.version=1.8.0_121
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=en_US
Framework arguments:  -product org.eclipse.epp.package.jee.product
Command-line arguments:  -os win32 -ws win32 -arch x86_64 -product org.eclipse.epp.package.jee.product -data C:\dev\eclipse\jee.neon.3.3\ws0 -clean

Exception Stack Trace:
java.lang.StackOverflowError
	at org.eclipse.wst.xml.core.internal.catalog.Catalog$InternalResolver.resolveRewrite(Catalog.java:303)
	at org.eclipse.wst.xml.core.internal.catalog.Catalog$InternalResolver.resolveURI(Catalog.java:368)
	at org.eclipse.wst.xml.core.internal.catalog.Catalog.resolveURI(Catalog.java:759)
	at org.eclipse.wst.xml.core.internal.catalog.Catalog.resolveSubordinateCatalogs(Catalog.java:736)
	at org.eclipse.wst.xml.core.internal.catalog.Catalog$InternalResolver.resolveURI(Catalog.java:380)
	at org.eclipse.wst.xml.core.internal.catalog.Catalog.resolveURI(Catalog.java:759)
	at org.jboss.tools.jst.web.kb.taglib.TagLibraryManager.getStaticTLD(TagLibraryManager.java:92)
	at org.jboss.tools.jst.web.kb.internal.StaticLibraries.getLibraries(StaticLibraries.java:44)
	at org.jboss.tools.jst.web.kb.internal.KbProject.getTagLibraries(KbProject.java:135)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getCompositeLibraries(FaceletTagLibrary.java:90)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:128)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)
	at org.jboss.tools.jst.web.kb.internal.taglib.FaceletTagLibrary.getComponent(FaceletTagLibrary.java:130)

	[... the stack trace goes on and on...]