From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#18285: 24.3.92; A combination of `display' on text and `invisible' and `before/after-string' leads to the before/after string being displayed twice Date: Thu, 21 Aug 2014 19:06:42 +0300 Message-ID: <83mwaxbze5.fsf@gnu.org> References: <86d2bypwx1.fsf@yandex.ru> <83k365defw.fsf@gnu.org> <53F5FD0B.1070800@yandex.ru> <83ppftc2kv.fsf@gnu.org> <53F6130A.5090102@yandex.ru> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1408637252 16656 80.91.229.3 (21 Aug 2014 16:07:32 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 21 Aug 2014 16:07:32 +0000 (UTC) Cc: 18285@debbugs.gnu.org To: Dmitry Gutov Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Thu Aug 21 18:07:21 2014 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XKUtT-0007sG-17 for geb-bug-gnu-emacs@m.gmane.org; Thu, 21 Aug 2014 18:07:19 +0200 Original-Received: from localhost ([::1]:33182 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XKUtS-00020Y-JT for geb-bug-gnu-emacs@m.gmane.org; Thu, 21 Aug 2014 12:07:18 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:34611) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XKUtK-0001zX-4m for bug-gnu-emacs@gnu.org; Thu, 21 Aug 2014 12:07:15 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XKUtC-0001mG-R8 for bug-gnu-emacs@gnu.org; Thu, 21 Aug 2014 12:07:10 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:42143) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XKUtC-0001mC-Nt for bug-gnu-emacs@gnu.org; Thu, 21 Aug 2014 12:07:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1XKUtC-0006RI-77 for bug-gnu-emacs@gnu.org; Thu, 21 Aug 2014 12:07:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 21 Aug 2014 16:07:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 18285 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 18285-submit@debbugs.gnu.org id=B18285.140863721424732 (code B ref 18285); Thu, 21 Aug 2014 16:07:02 +0000 Original-Received: (at 18285) by debbugs.gnu.org; 21 Aug 2014 16:06:54 +0000 Original-Received: from localhost ([127.0.0.1]:49086 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XKUt3-0006Qq-D4 for submit@debbugs.gnu.org; Thu, 21 Aug 2014 12:06:53 -0400 Original-Received: from mtaout28.012.net.il ([80.179.55.184]:46413) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1XKUt0-0006QV-6z for 18285@debbugs.gnu.org; Thu, 21 Aug 2014 12:06:51 -0400 Original-Received: from conversion-daemon.mtaout28.012.net.il by mtaout28.012.net.il (HyperSendmail v2007.08) id <0NAN00K00Z2SON00@mtaout28.012.net.il> for 18285@debbugs.gnu.org; Thu, 21 Aug 2014 19:05:52 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by mtaout28.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0NAN00CARZDSAE90@mtaout28.012.net.il>; Thu, 21 Aug 2014 19:05:52 +0300 (IDT) In-reply-to: <53F6130A.5090102@yandex.ru> X-012-Sender: halo1@inter.net.il X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:92573 Archived-At: > Date: Thu, 21 Aug 2014 19:40:58 +0400 > From: Dmitry Gutov > CC: 18285@debbugs.gnu.org > > >> After all, that was the intention behind the code I encountered this bug > >> in. And with the current logic, like you say, if `display' is set, > >> `invisible' is redundant. > > > > Yes, but not the other way around. > > If the `invisible' starts even one character earlier, it *is* the other > way around. Yes, because then there's no doubt about the order of evaluating the various properties and acting upon them. By contrast, when they all begin at the same buffer position, the order is implementation-defined. The code is written to examine display properties before the invisible properties. > >> Thanks. That looks very much like a bug as well, though maybe again, too > >> expensive to fix. FWIW, for that issue, if myov2 has higher priority > >> than myov1 (if only by virtue of being inside and shorter), I'd display > >> just "STRING2" ("STRING1" would not be visible at all). But that's just > >> going by logic; maybe there's a use case that would break. > > > > I'm quite sure there's some use case somewhere that will break. > > Maybe. But at least it's consistent with the overlay priority rules. The priority is _per_buffer_position_. We tend to forget that text properties and overlays in Emacs are _character_ properties, but the display engine is designed and implemented to support that, and in some obscure cases, like this one, it is impossible to understand its logic, unless one remembers this simple fact.