[Emacs-diffs] emacs-24 r117210: Document incompatible overlay priority change

[Glenn Morris]

------------------------------------------------------------
revno: 117210
revision-id: address@hidden
parent: address@hidden
fixes bug: http://debbugs.gnu.org/17234
committer: Glenn Morris <address@hidden>
branch nick: emacs-24
timestamp: Thu 2014-06-05 23:45:16 -0700
message:
  Document incompatible overlay priority change
  
  * doc/lispref/display.texi (Overlay Properties): Update re priority. 
  
  * etc/NEWS: Related edit.
modified:
  doc/lispref/ChangeLog          changelog-20091113204419-o5vbwnq5f7feedwu-6155
  doc/lispref/display.texi       
display.texi-20091113204419-o5vbwnq5f7feedwu-6172
  etc/NEWS                       news-20100311060928-aoit31wvzf25yr1z-1

=== modified file 'doc/lispref/ChangeLog'
--- a/doc/lispref/ChangeLog     2014-06-05 06:15:44 +0000
+++ b/doc/lispref/ChangeLog     2014-06-06 06:45:16 +0000
@@ -1,3 +1,7 @@
+2014-06-06  Glenn Morris  <address@hidden>
+
+       * display.texi (Overlay Properties): Update re priority.  (Bug#17234)
+
 2014-06-05  Glenn Morris  <address@hidden>
 
        * package.texi (Package Archives): Mention signing packages.

=== modified file 'doc/lispref/display.texi'
--- a/doc/lispref/display.texi  2014-05-17 08:58:17 +0000
+++ b/doc/lispref/display.texi  2014-06-06 06:45:16 +0000
@@ -1515,9 +1515,9 @@
 @table @code
 @item priority
 @kindex priority @r{(overlay property)}
-This property's value determines the priority of the overlay.  No priority, or
address@hidden, 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 @@
 override the face attributes of the lower priority @code{face}
 property.
 
-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)}

=== modified file 'etc/NEWS'
--- a/etc/NEWS  2014-06-05 06:15:44 +0000
+++ b/etc/NEWS  2014-06-06 06:45:16 +0000
@@ -1149,6 +1149,12 @@
 
 * 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 @@
 
 * 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.