Improve description of face merging

* doc/lispref/display.texi (Displaying Faces): More accurate
description of merging face attributes of "underlying text".
(Bug#1222)

1 files changed, 6 insertions, 5 deletions

diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index fd6820897f3..64b24f712ae 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -2949,11 +2949,12 @@ For a header line, Emacs applies the @code{header-line} face.
 If the text comes from an overlay string via @code{before-string} or
 @code{after-string} properties (@pxref{Overlay Properties}), or from a
 display string (@pxref{Other Display Specs}), and the string doesn't
-contain a @code{face} or @code{mouse-face} property, but the buffer
-text affected by the overlay/display property does define a face,
-Emacs applies the face attributes of the ``underlying'' buffer text.
-Note that this is so even if the overlay or display string is
-displayed in the display margins (@pxref{Display Margins}).
+contain a @code{face} or @code{mouse-face} property, or these
+properties leave some face attributes undefined, but the buffer text
+affected by the overlay/display property does define a face or those
+attributes, Emacs applies the face attributes of the ``underlying''
+buffer text.  Note that this is so even if the overlay or display
+string is displayed in the display margins (@pxref{Display Margins}).
 
 @item
 If any given attribute has not been specified during the preceding