Though the files are not in the current Android code tree, they were used in the two versions that currently make up more than half of the Android phones in use, he noted.
"From a legal point of view, you can't make an infringement undone only by removing it from one particular set of files -- you just avoid additional damage," Mueller said in an e-mail interview.
Oracle filed the lawsuit in August, claiming that Google's Android operating system infringes on Java copyrights that Oracle acquired when it bought Sun. Google has called the suit baseless, denying infringement.
If Google is found to infringe, it could be required to pay Oracle a licensing fee for each handset made that uses Android. It could pass that cost on to device vendors, but that would diminish the attractiveness of Android as a free operating system.
Android, which has grown dramatically in popularity over the past year, is under legal attack from many companies. Other Android-related lawsuits include Apple's suit against HTC; Microsoft's suit against Motorola; and Gemalto's suit against Google, Motorola, HTC and Samsung.
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