; Improve documentation of 'line-prefix' and 'wrap-prefix'.

* doc/lispref/text.texi (Special Properties): Spell out more
accurately how 'line-prefix' and 'wrap-prefix' properties should
be set.

(cherry picked from commit 87389f9ff9069f8e3b11ea0ff2e55619763c2231)

diff --git a/doc/lispref/text.texi b/doc/lispref/text.texi
index 626f39f3cd69b5f1fd8793afe0f18835151eea7a..460d3df6f0c7704f3400d25d26545f41cd295b1e 100644 (file)
--- a/doc/lispref/text.texi
+++ b/doc/lispref/text.texi
@@ -3857,13 +3857,19 @@ controls the total height of the display line ending in that newline.
 @xref{Line Height}.
 
 @item wrap-prefix
-If text has a @code{wrap-prefix} property, the prefix it defines will
-be added at display time to the beginning of every continuation line
-due to text wrapping (so if lines are truncated, the wrap-prefix is
-never used).  It may be a string or an image (@pxref{Other Display
-Specs}), or a stretch of whitespace such as specified by the
-@code{:width} or @code{:align-to} display properties (@pxref{Specified
-Space}).
+If a region of text has a @code{wrap-prefix} property, the prefix it
+defines will be added at display time to the beginning of every
+continuation line due to text wrapping (so if lines are truncated, the
+wrap-prefix is never used).  The property value may be a string or an
+image (@pxref{Other Display Specs}), or a stretch of whitespace such as
+specified by the @code{:width} or @code{:align-to} display properties
+(@pxref{Specified Space}).  Note that to have its effect, the
+@code{wrap-prefix} property must be set on the entire region of text,
+starting from the first character of the first line of that text and up
+to the last character of the last line; otherwise, breaking the text
+into lines in a different way might fail to display the prefix, because
+the display engine checks for this property only immediately after
+continuing a line.
 
 A wrap-prefix may also be specified for an entire buffer using the
 @code{wrap-prefix} buffer-local variable (however, a
@@ -3871,12 +3877,18 @@ A wrap-prefix may also be specified for an entire buffer using the
 the @code{wrap-prefix} variable).  @xref{Truncation}.
 
 @item line-prefix
-If text has a @code{line-prefix} property, the prefix it defines will
-be added at display time to the beginning of every non-continuation
-line.  It may be a string or an image (@pxref{Other Display
-Specs}), or a stretch of whitespace such as specified by the
-@code{:width} or @code{:align-to} display properties (@pxref{Specified
-Space}).
+If a region of text has a @code{line-prefix} property, the prefix it
+defines will be added at display time to the beginning of every
+non-continuation line.  The property value may be a string or an image
+(@pxref{Other Display Specs}), or a stretch of whitespace such as
+specified by the @code{:width} or @code{:align-to} display properties
+(@pxref{Specified Space}).  Note that to have its effect, the
+@code{line-prefix} property must be set on the entire region of text,
+starting from the first character of the first line of that text and up
+to the last character of the last line; otherwise, breaking the text
+into lines in a different way might fail to display the prefix, because
+the display engine checks for this property only when starting a new
+line.
 
 A line-prefix may also be specified for an entire buffer using the
 @code{line-prefix} buffer-local variable (however, a