bug#19551: 25.0.50; No lighter shown for `text-scale-mode' when it should be `+0'

[Stephen Berman <stephen.berman@gmx.net>]

On Fri, 9 Jan 2015 14:18:53 -0800 (PST) Drew Adams <drew.adams@oracle.com> wrote:

> I don't know how or why this happens, but when buffer text is zoomed out
> and back in, so that the resulting text scale is neutral (100%, zero
> increase/decrease), the mode-line lighter should say `+0', as specified
> in the code (`face-remap.el').  For some reason, the lighter just
> disappears, as if the value of `text-scale-mode-lighter' were nil.

I don't think this is a bug.  If I understand the code correctly, the
lighter disappears because the minor mode is turned off when the text
scale is 0; see this line in `text-scale-increase':

(text-scale-mode (if (zerop text-scale-mode-amount) -1 1))

I also don't see anywhere in face-remap.el that specifies the lighter is
"+0" when the text scale is 0 (the default value of
`text-scale-mode-lighter' is "+0", but changes as soon as
text-scale-mode is enabled).

Steve Berman