The licensing part of the patch README file is:
Patch Kit, Version 2.0
Copyright (c) 1988, Larry Wall
You may copy the patch kit in whole or in part as long as you don't try to
make money off it, or pretend that you wrote it.
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It may also be of interest to note that upstream XFree86 has not modified
any of the original source tarballs of 4.1.0 to remove this.