Created attachment 29215 [details]
Modified files from the ROOT webapp

According to XSDs (jsp_2_0.xsd, jsp_2_1.xsd, jsp_2_2.xsd), the "url-pattern" can occur more than once in the same "jsp-property-group".

[[[
  <xsd:complexType name="jsp-property-groupType">
...
      <xsd:element name="url-pattern"
                   type="javaee:url-patternType"
                   maxOccurs="unbounded"/>
]]]

There are three places where the "jsp-property-group" element is represented by an object in Tomcat:

a) in Jasper, o.a.jasper.compiler.JspConfig$JspPropertyGroup
b) in Catalina, o.a.catalina.deploy.JspPropertyGroup
c) in Servlet 3.0 API, javax.servlet.descriptor.JspPropertyGroupDescriptor (implemented by o.a.c.core.ApplicationJspPropertyGroupDescriptor)

The implementations in a) and c) are correct ones,  but in b) the collection of url patterns is mistakenly represented by a single value and setUrlPattern() method.

As the "setUrlPattern" method is called by digester (configured in o.a.c.startup.WebRuleSet), only the last url-pattern value survives.



The observable consequences of this issue:
===========================================
1. Merged web.xml is reproduced and passed to Jasper incorrectly.

(Currently it is passed only when metadata-complete="false" or absent, as I noted in Re:r1371995 on dev@, which is a different issue but it hides the effect of this one).

2. A known feature is that the paths mentioned in jsp-property-group are implicitly mapped to the JspServlet. Due to this issue this mapping occurs only for the last url-pattern.
(in WebXml#configureContext())


To reproduce in current 7.0.x (7.0.29 is affected):
====================================================
1. Unpack attached archive and put the files into the ROOT webapp.
The files are context.xml with <Context logEffectiveWebXml="true"/>
and web.xml without metadata-compete attribute and adding the following:
[[[
  <jsp-config>
    <jsp-property-group>
      <url-pattern>*.foo</url-pattern>
      <url-pattern>*.bar</url-pattern>
      <is-xml>true</is-xml>
    </jsp-property-group>
  </jsp-config>
]]]

2. Start Tomcat and look into the "catalina.`date`.log" file. The merged web.xml should have been dumped there. Look for the "jsp-property-group" element.
Actual result:

[[[
  <jsp-config>
    <jsp-property-group>
      <url-pattern>*.bar</url-pattern>
      <is-xml>true</is-xml>
    </jsp-property-group>
  </jsp-config>
]]]

Expected result: both *.foo and *.bar should be mentioned.


Tomcat 6 does not have this issue, because there is no such object in Catalina there. The digester configured in WebRuleSet calls StandardContext.addJspMapping(..), which is additive.