Subject: bug#152: window-line-height returns spurious OFFBOT values

From: Chong Yidong <[email-masked]>
Date: Sun, 20 Apr 2008 10:45:40 -0400

This appears to be a bug in the new font code.  When Emacs 23 uses a
non-fontconfig font, say:

Emacs.Font: -misc-fixed-medium-r-normal--13-*-*-*-c-70-iso8859-1

then (window-line-height -1) returns a non-zero OFFBOT element, saying
that the last line contains offscreen pixels, when in fact the last line
is completely inside the window.

To reproduce:

  (global-set-key [f1] (lambda () (interactive)
    (message (prin1-to-string (window-line-height -1)))))

Typing f1 in the scratch buffer gives me, e.g.,

  (9 39 510 4)
            ^

Emacs 22, using the exact same font in .Xresources, correctly returns a
zero OFFBOT.

Furthermore, Emacs 23, using a fontconfig font (Monospace-9), also
correctly returns a zero OFFBOT.