Fix a bug that could lead to duplicate links being recorded for tags.

Here I was bitten by perl's aliasing of foreach variables
to the loop array contents, and match_link accidentially changed
the contents of %links.

In Jon's testcase, a tag added an absolute link, which was
made relative by the above bug, and then the link was added
again in preprocess, and turned into a duplicate.

0 files changed, 0 insertions, 0 deletions