Regression: WebMetaDataParser gives error on war with no version info in web.xml

$unzip -p ~/temp/Calendar.war WEB-INF/web.xml
<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app>
<display-name>gwt-Calendar Compiled: Sun Jan 27 06:17:26 GMT 2008</display-name>
<description>Google Web Toolkit Project</description>
</web-app>

16:35:07,788 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-1) Starting deployment of "Calendar.war"
16:35:08,023 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-4) MSC00001: Failed to start service jboss.deployment.unit."Calendar.war".PARSE: org.jboss.msc.service.StartException in service jboss.deployment.unit."Calendar.war".PARSE: Failed to process phase PARSE of deployment "Calendar.war"
	at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:121) [jboss-as-server-7.1.0.CR1-SNAPSHOT.jar:]
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1824) [jboss-msc-1.0.1.GA.jar:]
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1759) [jboss-msc-1.0.1.GA.jar:]
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [:1.6.0_29]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [:1.6.0_29]
	at java.lang.Thread.run(Thread.java:680) [:1.6.0_29]
Caused by: java.lang.IllegalStateException: Cannot obtain servlet version
	at org.jboss.metadata.parser.servlet.WebMetaDataParser.parse(WebMetaDataParser.java:103)
	at org.jboss.metadata.parser.servlet.WebMetaDataParser.parse(WebMetaDataParser.java:54)
	at org.jboss.as.web.deployment.WebParsingDeploymentProcessor.deploy(WebParsingDeploymentProcessor.java:87)
	at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:115) [jboss-as-server-7.1.0.CR1-SNAPSHOT.jar:]
	... 5 more