uncompressed archives with HTML file as an entry can be rejected by file content validation

Fire up Nexus 2.7.2, and retrieve this URL:

http://localhost:8081/nexus/content/groups/public/com/intellij/annotations/7.0.3/annotations-7.0.3.jar

This works.

Now try the same with Nexus 2.8.0. This will fail, the artifact is rejected by file content validation. I'm not sure why, the magic number is correct, and various zip programs I tried (including jar) unpack it without complaint.

jvm 1 | 2014-04-29 09:15:15,818-0500 INFO [qtp128766849-84] admin org.sonatype.nexus.proxy.maven.maven2.M2Repository - Proxied item central:/com/intellij/annotations/7.0.3/annotations-7.0.3.jar evaluated as INVALID during content validation (validator=filetypevalidator, sourceUrl=https://secure.central.sonatype.com/maven2/com/intellij/annotations/7.0.3/annotations-7.0.3.jar)