Please forgive for the lack of brevity, but I have to get this off my
chest...

This bug is very minor. In order to manifest itself, the following
conditions have to be met:

* You must create a diagonal matrix

* You must index the first row or column of this diagonal matrix
(indexing any other row or column won't trigger the bug)

* You must take this row or column vector, internally represented
as a diagonal matrix, and you must feed it back into the diag
function.

All three conditions at once are rare. Moreover, there is a simple
workaround: use diag(full(e1)) instead of diag(e1), and this
workaround doesn't affect semantics in Matlab.

I have a fix for this bug. It is for the development version, since I
could not do it cleanly without breaking API, and we cannot break API
for the stable version. It will thus have to wait until we can make
another major release.

However, it took me a long time to fix this bug. About 6 hours. I
don't really care about this bug, but I felt driven to fix it because
apparently two people care enough about the bug report it and assure
me that it happens in several places and that it's annoying and
counterintuitive bug. I disagree. It's a very minor bug that was
annoying to fix. I am therefore proposing the following: I will not
release my fix unless the people who care about having this bug fixed
tip me at my Paypal address: jordigh@octave.org. If you send me any
nonzero monetary reward for the time I've spent fixing this bug, I
will gladly apply my fix to the development version. If the amount is
of sufficient magnitude, I may reconsider reworking my fix so that it
doesn't break API and can go into the stable version, which will be
released much sooner than the next major version.

Alternatively, if paying me for fixing this bug is an insurmountable
financial burden for you, you may provide your own patch for this bug.
If the patch does not break anything important in Octave and it
follows our coding standards, I will gladly apply it.

I hope you agree this is a reasonable request.

This is fairly esoteric. Is this actually causing you any real trouble?