javadoc uses static non-final fields. This affects repeatability and reentrancy. These fields should be investigated.

com.sun.tools.doclets.internal.toolkit.builders.AbstractBuilder: field containingPackagesSeen is static and not final
com.sun.tools.doclets.internal.toolkit.builders.LayoutParser: field instance is static and not final
com.sun.tools.doclets.internal.toolkit.util.Util: field whitespace is static and not final
com.sun.tools.doclets.formats.html.ConfigurationImpl: field instance is static and not final
com.sun.tools.doclets.formats.html.SourceToHTMLConverter: field relativePath is static and not final
com.sun.tools.doclets.formats.html.markup.DocType: field transitional is static and not final
com.sun.tools.doclets.formats.html.markup.DocType: field frameset is static and not final
com.sun.tools.javadoc.ParamTagImpl: field typeParamRE is static and not final