EVALUATION

This issue seems to be tickled by the fact that 2 files of the same name "README.html" changed in the JDK image for a single update release.

This happened between 6u4-b02 and 6u4-b03.  The patcher generates 2 patches for files named README.html, but it gets confused when there is only one README.html in the jdk-image (because the user unselected the D&S feature).  It uses the wrong patch on the wrong README.html file.  Here's an email I sent to jdk-core, which describes a bit more:

Someone asked during the meeting why the patching error is only happening when we deselect the "Demos and Samples" (D&S) feature, and not when it's selected.  I had to think about it a little more.  This is 3rd party RTPatch software, but here is my theory of what's happening.

We generate a patch binary for the files that changed between 2 releases.  There at least 2 README.html files that needed patching from b02->b03:

jdk-image/README.html
jdk-image/demo/jfc/CodePointIM/README.html

So the patcher will have individual patches for these 2 files.  The patcher will try and patch the demo one first, because it patches in alphabetical order.  There are 2 scenarios here, one where D&S feature is selected and one where the user unselects the D&S feature.

UN-selected D&S scenario:
   Because the D&S feature is UN-selected, the machine only has 1 README.html file in the JDK image that's about to be patched:  jdk-image/README.html.  The patcher will see the name jdk-image/README.html, and it will incorrectly patch it with the patch for jdk-image/demo/jfc/CodePointIM/README.html, which is an incorrect mismatch.  That's why the error is popping up.

Selected D&S scenario:
   Because the D&S feature is selected, the machine has 2 files in the JDK image that are about to be patched: jdk-image/README.html & jdk-image/demo/jfc/CodePointIM/README.html.  The first README.html file that it finds alphabetically in the jdk-image is the correct one:  jdk-image/demo/jfc/CodePointIM/README.html.  And now both files get patched successfully.