Hi, I got the following strange behaviour in the regexp matching on
XEmacs/Mule on HP-UX and XEmacs on Windows-NT: the only difference is
\\(ab\\|dg\\)\\| vs ab\\|dg\\| at the beginning...
Unfortunately the regexp matching code contains a few subtle bugs.
Stefan Monnier did quite a lot of work on the FSF regexp engine to fix
those. I have already two aborted attempts at merging those in,
unfortunately it is neither the most trivial nor the most maintainable
bit of code.