Re: Bug: Unable to request replace-string of " \t"

[Richard Stallman <rms@gnu.org>]

    I wasn't sure it works for the `tab' key (mapped to TAB via
    function-key-map), but it looks like the `ascii-character' property on the
    `tab' symbol does make it work, so maybe that's a better choice.  I don't
    care either way, the main question is whether to override the usual binding.

What binding did it have in Emacs 21?  And why was it changed?

    I believe it's a side-effect of a change I made a while back which changed
    the global indent-line-function from indent-to-left-margin (used for
    paragraph-indent-text-mode) to indent-relative (used for the "new"
    text-mode, formerly known as indent-text-mode).

In that case, since it was not changed intentionally, definitely let's
change it back.