Two more overlay display bugs

Two more overlay display bugs

[Richard Stallman]

Would someone please fix these, then ack?

To: bug-gnu-emacs@gnu.org
From: Joe Wells <jbw@macs.hw.ac.uk>
Date: Sat, 20 Oct 2007 06:32:19 +0100
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Subject: two display bugs involving interactions between after-string and
	display properties of adjacent overlays

Here are two more display bugs I found while trying to improve the
code in tex-fold.el in AUCTeX.

These bugs involve interactions between after-string and display
properties of adjacent overlays.

I'm assuming this macro in my reproduction code below:

  (defmacro test-in-fresh-buffer-and-window (&rest body)
    `(progn
       (delete-other-windows)
       (kill-buffer (get-buffer-create "xyzzy"))
       (let ((xyzzy-buf (get-buffer-create "xyzzy")))
         (set-buffer xyzzy-buf)
         (display-buffer xyzzy-buf)
         ,@body
         )))

BUG #1:  An overlay's after-string property that would appear at the
end of the buffer is not displayed, if the same overlay also has a
display property and an immediately preceding overlay also has an
after-string property.  (Putting extra characters at the end of the
buffer works around this bug.)

Reproduce with this expression:

  (test-in-fresh-buffer-and-window
   (insert "AB")
   (let ((o1 (make-overlay 1 2))
         (o2 (make-overlay 2 3)))
     (overlay-put o1 'after-string "1")
     (overlay-put o2 'after-string "2")
     (overlay-put o2 'display "b")
     ))

The above expression should display ?A1b2?.
The above expression wrongly actually displays ?A1b?.

BUG #2:  An overlay's display property and after-string property are
not displayed if an immediately following overlay shares the same Lisp
string as its display property.  (Using two distinct display strings
with identical contents works around the bug.)

Reproduce with this expression:

  (test-in-fresh-buffer-and-window
   (insert "ABCD")
   (let ((o1 (make-overlay 2 3))
         (o2 (make-overlay 3 4))
         (s #1=" "))
     (overlay-put o1 'after-string "1")
     (overlay-put o1 'display #1#)
     (overlay-put o2 'display #1#)))

The above expression should display ?A 1 D?.
The above expression wrongly actually displays ?A D?.

I hope these bug reports are helpful.

Joe

======================================================================
In GNU Emacs 22.1.1 (i686-pc-linux-gnu, GTK+ Version 2.8.20)
 of 2007-06-27 on artemis
Windowing system distributor `The X.Org Foundation', version 11.0.70000000
configured using `configure  '--prefix=/home/jbw/local2' '--enable-debug' '--disable-nls' '--with-x-toolkit=gtk' 'CFLAGS=-O0 -g3 -ggdb''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: en_US.UTF-8
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: jbw
  value of $LANG: nil
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

Minor modes in effect:
  TeX-source-specials-mode: t
  outline-minor-mode: t
  desktop-save-mode: t
  url-handler-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  auto-compression-mode: t
  temp-buffer-resize-mode: t
  size-indication-mode: t
  line-number-mode: t
  transient-mark-mode: t

bug#1200: marked as done (Two more overlay display bugs)

[Emacs bug Tracking System]

[-- Attachment #1: Type: text/plain, Size: 847 bytes --]


Your message dated Sun, 19 Oct 2008 17:11:12 -0400
with message-id <18683.41584.520431.671377@fencepost.gnu.org>
and subject line Re: bug#1200: Two more overlay display bugs
has caused the Emacs bug report #1200,
regarding Two more overlay display bugs
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact don@donarmstrong.com
immediately.)


-- 
1200: http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=1200
Emacs Bug Tracking System
Contact don@donarmstrong.com with problems

[-- Attachment #2: Type: message/rfc822, Size: 4377 bytes --]

From: Richard Stallman <rms@gnu.org>
To: emacs-pretest-bug@gnu.org
Subject: Two more overlay display bugs
Date: Sun, 19 Oct 2008 01:00:36 -0400
Message-ID: <E1IjVDL-00018n-0P@fencepost.gnu.org>

Here are bugs that were reported a year ago
which I think should not be forgotten.

To: bug-gnu-emacs@gnu.org
From: Joe Wells <jbw@macs.hw.ac.uk>
Date: Sat, 20 Oct 2007 06:32:19 +0100
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Subject: two display bugs involving interactions between after-string and
	display properties of adjacent overlays

Here are two more display bugs I found while trying to improve the
code in tex-fold.el in AUCTeX.

These bugs involve interactions between after-string and display
properties of adjacent overlays.

I'm assuming this macro in my reproduction code below:

  (defmacro test-in-fresh-buffer-and-window (&rest body)
    `(progn
       (delete-other-windows)
       (kill-buffer (get-buffer-create "xyzzy"))
       (let ((xyzzy-buf (get-buffer-create "xyzzy")))
         (set-buffer xyzzy-buf)
         (display-buffer xyzzy-buf)
         ,@body
         )))

BUG #1:  An overlay's after-string property that would appear at the
end of the buffer is not displayed, if the same overlay also has a
display property and an immediately preceding overlay also has an
after-string property.  (Putting extra characters at the end of the
buffer works around this bug.)

Reproduce with this expression:

  (test-in-fresh-buffer-and-window
   (insert "AB")
   (let ((o1 (make-overlay 1 2))
         (o2 (make-overlay 2 3)))
     (overlay-put o1 'after-string "1")
     (overlay-put o2 'after-string "2")
     (overlay-put o2 'display "b")
     ))

The above expression should display ?A1b2?.
The above expression wrongly actually displays ?A1b?.

BUG #2:  An overlay's display property and after-string property are
not displayed if an immediately following overlay shares the same Lisp
string as its display property.  (Using two distinct display strings
with identical contents works around the bug.)

Reproduce with this expression:

  (test-in-fresh-buffer-and-window
   (insert "ABCD")
   (let ((o1 (make-overlay 2 3))
         (o2 (make-overlay 3 4))
         (s #1=" "))
     (overlay-put o1 'after-string "1")
     (overlay-put o1 'display #1#)
     (overlay-put o2 'display #1#)))

The above expression should display ?A 1 D?.
The above expression wrongly actually displays ?A D?.

I hope these bug reports are helpful.

Joe

======================================================================
In GNU Emacs 22.1.1 (i686-pc-linux-gnu, GTK+ Version 2.8.20)
 of 2007-06-27 on artemis
Windowing system distributor `The X.Org Foundation', version 11.0.70000000
configured using `configure  '--prefix=/home/jbw/local2' '--enable-debug' '--disable-nls' '--with-x-toolkit=gtk' 'CFLAGS=-O0 -g3 -ggdb''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: en_US.UTF-8
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: jbw
  value of $LANG: nil
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

Minor modes in effect:
  TeX-source-specials-mode: t
  outline-minor-mode: t
  desktop-save-mode: t
  url-handler-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  auto-compression-mode: t
  temp-buffer-resize-mode: t
  size-indication-mode: t
  line-number-mode: t
  transient-mark-mode: t




[-- Attachment #3: Type: message/rfc822, Size: 2303 bytes --]

From: Glenn Morris <rgm@gnu.org>
To: 1200-done@emacsbugs.donarmstrong.com
Subject: Re: bug#1200: Two more overlay display bugs
Date: Sun, 19 Oct 2008 17:11:12 -0400
Message-ID: <18683.41584.520431.671377@fencepost.gnu.org>


Richard Stallman wrote (on Sun, 19 Oct 2008 at 01:00 -0400):

> BUG #1:  An overlay's after-string property that would appear at the
> end of the buffer is not displayed, if the same overlay also has a
> display property and an immediately preceding overlay also has an
> after-string property.  (Putting extra characters at the end of the
> buffer works around this bug.)

This was fixed in Emacs 22.3. The relevant change is

2008-03-31  Chong Yidong  <cyd@stupidchicken.com>

        * xdisp.c (next_overlay_string): Don't set
        overlay_strings_at_end_processed_p if we're currently reading
        from a display string.

> BUG #2:  An overlay's display property and after-string property are
> not displayed if an immediately following overlay shares the same Lisp
> string as its display property.  (Using two distinct display strings
> with identical contents works around the bug.)

I have split this into a separate bug.

bug#1208: overlay after-string and adjacent overlays with same string

[Glenn Morris]

tags 1208 wontfix
stop

> BUG #2:  An overlay's display property and after-string property are
> not displayed if an immediately following overlay shares the same Lisp
> string as its display property.  (Using two distinct display strings
> with identical contents works around the bug.)

Tagging as wontfix based on the previous discussion:

http://lists.gnu.org/archive/html/bug-gnu-emacs/2008-02/msg00179.html

    This occurs because, as stated in the Emacs Lisp manual, all
    consecutive characters that have the same Lisp object as their
    `display' property are replaced as a single unit.  In this case, it's
    somewhat ambiguous what the behavior should be, but after looking at
    the code I think the behavior you suggest would be much more difficult
    to implement (and slower) than the current behavior.

    Furthermore, you can trivially obtain the behavior you want by making
    a copy of the string using copy-sequence, so that the two display
    strings are different Lisp objects.

    Therefore, let's leave this alone.

Processed: Re: bug#1208: overlay after-string and adjacent overlays with same string

[Emacs bug Tracking System]

Processing commands for control@emacsbugs.donarmstrong.com:

> tags 1208 wontfix
bug#1208: overlay after-string and adjacent overlays with same string
There were no tags set.
Tags added: wontfix

> stop
Stopping processing here.

Please contact me if you need assistance.

Don Armstrong
(administrator, Emacs bugs database)

bug#1201: marked as done (Another overlay display bug)

[Emacs bug Tracking System]

[-- Attachment #1: Type: text/plain, Size: 816 bytes --]


Your message dated Fri, 24 Oct 2008 15:01:08 -0400
with message-id <87mygtn7gr.fsf@cyd.mit.edu>
and subject line Re: Another overlay display bug
has caused the Emacs bug report #1201,
regarding Another overlay display bug
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact don@donarmstrong.com
immediately.)


-- 
1201: http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=1201
Emacs Bug Tracking System
Contact don@donarmstrong.com with problems

[-- Attachment #2: Type: message/rfc822, Size: 3144 bytes --]

From: Richard Stallman <rms@gnu.org>
To: emacs-pretest-bug@gnu.org
Subject: Another overlay display bug
Date: Sun, 19 Oct 2008 01:00:55 -0400
Message-ID: <E1IjVDL-00018n-0P@fencepost.gnu.org>

Here's another bug that was reported a year ago
which I think should not be forgotten.

From: Richard Stallman <rms@gnu.org>
Content-Type: text/plain; charset=ISO-8859-15
To: emacs-devel@gnu.org
Subject: Another overlay display bug
Reply-To: rms@gnu.org
Message-Id: <E1IjVDM-0001BJ-AH@fencepost.gnu.org>
Date: Mon, 10 Dec 2007 10:19:14 -0500

Would someone please fix this, then ack?

To: bug-gnu-emacs@gnu.org
From: Joe Wells <jbw@macs.hw.ac.uk>
Date: Sat, 20 Oct 2007 06:43:43 +0100
In-Reply-To: <86k5pi9wrg.fsf@macs.hw.ac.uk> (Joe Wells's message of "Sat\,
	20 Oct 2007 06\:32\:19 +0100")
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Subject: Re: two display bugs involving interactions between after-string
	and display properties of adjacent overlays

Joe Wells <jbw@macs.hw.ac.uk> writes:

> Here are two more display bugs I found while trying to improve the
> code in tex-fold.el in AUCTeX.

Here is a third such bug.

> These bugs involve interactions between after-string and display
> properties of adjacent overlays.

Ditto.

> I'm assuming this macro in my reproduction code below:
>
>   (defmacro test-in-fresh-buffer-and-window (&rest body)
>     `(progn
>        (delete-other-windows)
>        (kill-buffer (get-buffer-create "xyzzy"))
>        (let ((xyzzy-buf (get-buffer-create "xyzzy")))
>          (set-buffer xyzzy-buf)
>          (display-buffer xyzzy-buf)
>          ,@body
>          )))

Ditto.

> BUG #1:  ...

> BUG #2:  ...

BUG #3:  An overlay's after-string property is not displayed if an
immediately following overlay has the empty string as its display
property.

Reproduce with this expression:

  (test-in-fresh-buffer-and-window
   (insert "ABCD")
   (let ((o1 (make-overlay 2 3))
         (o2 (make-overlay 3 4)))
     (overlay-put o1 'after-string "1")
     (overlay-put o2 'display "")))

The above expression should display ?AB1D?.
The above expression wrongly actually displays ?ABD?.

> ======================================================================
> In GNU Emacs 22.1.1 (i686-pc-linux-gnu, GTK+ Version 2.8.20) ...

Same details as in last message.

I hope this bug report is helpful.

-- 
Joe




[-- Attachment #3: Type: message/rfc822, Size: 919 bytes --]

From: Chong Yidong <cyd@stupidchicken.com>
To: 1201-done@emacsbugs.donarmstrong.com
Subject: Re: Another overlay display bug
Date: Fri, 24 Oct 2008 15:01:08 -0400
Message-ID: <87mygtn7gr.fsf@cyd.mit.edu>

I've checked in a fix.