[Emacs-diffs] master b8e18b6: Improve documentation of 'set-fontset-font'

[Eli Zaretskii]

branch: master
commit b8e18b63a3270090469b1092dea9520bb2c9a435
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    Improve documentation of 'set-fontset-font'
    
    * doc/lispref/display.texi (Fontsets): Document the value of nil
    for the 3rd argument of 'set-fontset-font'.
---
 doc/lispref/display.texi |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index 05bcd9f..b12995b 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -3304,6 +3304,9 @@ fontset, whose short name is @samp{fontset-default}.
 @var{character} may be a script name.  In that case, use
 @var{font-spec} for all character in the charsets.
 
address@hidden may be a font-spec object created by the function
address@hidden (@pxref{Low-Level Font}).
+
 @var{font-spec} may be a cons; @code{(@var{family} . @var{registry})},
 where @var{family} is a family name of a font (possibly including a
 foundry name at the head), @var{registry} is a registry name of a font
@@ -3311,6 +3314,12 @@ foundry name at the head), @var{registry} is a registry 
name of a font
 
 @var{font-spec} may be a font name string.
 
address@hidden may be @code{nil}, which explicitly specifies that
+there's no font for the specified @var{character}.  This is useful,
+for example, to avoid expensive system-wide search for fonts for
+characters that have no glyphs, like those from the Unicode Private
+Use Area (PUA).
+
 The optional argument @var{add}, if address@hidden, specifies how to
 add @var{font-spec} to the font specifications previously set.  If it
 is @code{prepend}, @var{font-spec} is prepended.  If it is