I think you should not show on screen how many characters user's password has,
if that is what you are looking for. Just white blank space without (visible)
cursor moving when password is typed, please.

Standard practice is to show the number of chars typed, otherwise people can't
effectively use backspace and think the keyboard isn't working. The mild
additional security risk is worth it.

I disagree. Unix logins has been working without showing password length for
years. I belive people understand this. BTW, what people are you refering to?
New users with Windows backgroud perhaps? And which standard says so, real or
some de-facto (= Windows)?

If you don't change it, I would appreciate if you made this optional i.e. I
could turn off the printing of those characters.

And comment to initial comment: Those "unknown glyph squares" with Finnish
locale look like this ASCII art:

|-----|
| 2 5 |
| C F |
|-----|

Perhaps that is the keycode, character number...

0x25cf is the Unicode circle character. But the font doesn't contain it so we 
get the boxes.

2.5.0.7-5 disables the circle thing again.

For adding the no-indicator-at-all config option, I wouldn't do it myself, but
in any case the right place to add config options is upstream on gnome.org - 
if we add Red Hat specific config option, it may not be supported in future
releases, which is a problem. http://bugzilla.gnome.org is the place to file 
gnome.org RFEs.

Stupid question: Is "circle thing" enabled in editable run-time configuration
file or is it compile-time option (which can not be changed without recompiling
gdm)?

If it's editable in configuration file, we don't need bother GNOME people.
If it's compile-time option then I will bother them.

Circles vs. asterisks is configurable in a config file. I don't think there's a
"nothing" option though.

So gdm version 2.5.0.7-5 shows asterisks instead of circles?

yes.

Latest version of gdm in a composed tree is gdm-2.4.0-7-10, which does indeed
show asterisks for the password characters.  Closing this out.