Commit 137dcb47 authored by Glenn Morris's avatar Glenn Morris
Browse files

Document incompatible overlay priority change

* doc/lispref/display.texi (Overlay Properties): Update re priority. 

* etc/NEWS: Related edit.

Fixes: debbugs:17234
parent 9f7c9816
2014-06-06 Glenn Morris <>
* display.texi (Overlay Properties): Update re priority. (Bug#17234)
2014-06-05 Glenn Morris <>
* package.texi (Package Archives): Mention signing packages.
......@@ -1515,9 +1515,9 @@ of them:
@table @code
@item priority
@kindex priority @r{(overlay property)}
This property's value determines the priority of the overlay. No priority, or
@code{nil}, means zero. A non-nil and non-integer value has
undefined behavior.
This property's value determines the priority of the overlay.
If you want to specify a priority value, use either @code{nil}
(or zero), or a positive integer. Any other value has undefined behavior.
The priority matters when two or more overlays cover the same
character and both specify the same property; the one whose
......@@ -1527,9 +1527,13 @@ completely override the other value; instead, its face attributes
override the face attributes of the lower priority @code{face}
Currently, all overlays take priority over text properties. Please
avoid using negative priority values, as we have not yet decided just
what they should mean.
Currently, all overlays take priority over text properties.
Note that Emacs sometimes uses non-numeric priority values for some of
its internal overlays, so do not try to do arithmetic on the
priority of an overlay (unless it is one that you created). If you
need to put overlays in priority order, use the @var{sorted} argument
of @code{overlays-at}. @xref{Finding Overlays}.
@item window
@kindex window @r{(overlay property)}
......@@ -1149,6 +1149,12 @@ low-level libraries gfilenotify.c, inotify.c or w32notify.c.
* Incompatible Lisp Changes in Emacs 24.4
** Do not assume that the priority of all overlays will be numeric.
(You should still only specify integer priorities on overlays you create.)
If you need to sort arbitrary overlays into priority order, `overlays-at'
can now optionally do this.
** `kill-region' has lost its `yank-handler' optional argument.
......@@ -1248,8 +1254,6 @@ the other.
* Lisp Changes in Emacs 24.4
** overlays-at can optionally sort its result by priority.
** The second argument of `eval' can now specify a lexical environment.
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