Clarify documentation of face attribute functions

* doc/lispref/display.texi (Attribute Functions): Make sure to
document that an omitted FRAME argument means the same as nil.
(Bug#24879)
This commit is contained in:
Eli Zaretskii 2016-11-05 10:54:15 +02:00
parent de51d59802
commit 3ef86fd063

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@ -2548,7 +2548,7 @@ modifying the attributes of a named face.
This function returns the value of the @var{attribute} attribute for
@var{face} on @var{frame}.
If @var{frame} is @code{nil}, that means the selected frame
If @var{frame} is omitted or @code{nil}, that means the selected frame
(@pxref{Input Focus}). If @var{frame} is @code{t}, this function
returns the value of the specified attribute for newly-created frames
(this is normally @code{unspecified}, unless you have specified some
@ -2644,8 +2644,8 @@ created frames.
The following commands and functions mostly provide compatibility
with old versions of Emacs. They work by calling
@code{set-face-attribute}. Values of @code{t} and @code{nil} for
their @var{frame} argument are handled just like
@code{set-face-attribute}. Values of @code{t} and @code{nil} (or
omitted) for their @var{frame} argument are handled just like
@code{set-face-attribute} and @code{face-attribute}. The commands
read their arguments using the minibuffer, if called interactively.
@ -2714,7 +2714,8 @@ name used for @var{character}.
@defun face-foreground face &optional frame inherit
@defunx face-background face &optional frame inherit
These functions return the foreground color (or background color,
respectively) of face @var{face}, as a string.
respectively) of face @var{face}, as a string. If the color is
unspecified, they return @code{nil}.
@end defun
@defun face-stipple face &optional frame inherit