From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#25863: 25.1; garbage display by small image Date: Sat, 25 Feb 2017 16:05:54 +0200 Message-ID: <83shn2qsal.fsf@gnu.org> References: <8737f2bmw2.fsf@gmail.com> <83varyqx88.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1488031635 12455 195.159.176.226 (25 Feb 2017 14:07:15 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 25 Feb 2017 14:07:15 +0000 (UTC) Cc: 25863@debbugs.gnu.org To: ynyaaa@gmail.com Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Sat Feb 25 15:07:10 2017 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1chd08-0002ZJ-Q2 for geb-bug-gnu-emacs@m.gmane.org; Sat, 25 Feb 2017 15:07:08 +0100 Original-Received: from localhost ([::1]:42864 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1chd0E-0006of-Rv for geb-bug-gnu-emacs@m.gmane.org; Sat, 25 Feb 2017 09:07:14 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:44607) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1chd05-0006fB-0w for bug-gnu-emacs@gnu.org; Sat, 25 Feb 2017 09:07:05 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1chd01-0001wj-UW for bug-gnu-emacs@gnu.org; Sat, 25 Feb 2017 09:07:05 -0500 Original-Received: from debbugs.gnu.org ([208.118.235.43]:57082) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1chd01-0001wd-Qp for bug-gnu-emacs@gnu.org; Sat, 25 Feb 2017 09:07:01 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1chd01-0005US-KC for bug-gnu-emacs@gnu.org; Sat, 25 Feb 2017 09:07:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 25 Feb 2017 14:07:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 25863 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 25863-submit@debbugs.gnu.org id=B25863.148803159521070 (code B ref 25863); Sat, 25 Feb 2017 14:07:01 +0000 Original-Received: (at 25863) by debbugs.gnu.org; 25 Feb 2017 14:06:35 +0000 Original-Received: from localhost ([127.0.0.1]:55281 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1chcza-0005Tm-OT for submit@debbugs.gnu.org; Sat, 25 Feb 2017 09:06:34 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:53529) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1chczZ-0005TT-IX for 25863@debbugs.gnu.org; Sat, 25 Feb 2017 09:06:33 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1chczT-0001dN-PA for 25863@debbugs.gnu.org; Sat, 25 Feb 2017 09:06:28 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:55448) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1chczL-0001Wt-4f; Sat, 25 Feb 2017 09:06:19 -0500 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:4404 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1chczK-0003SS-90; Sat, 25 Feb 2017 09:06:18 -0500 In-reply-to: <83varyqx88.fsf@gnu.org> (message from Eli Zaretskii on Sat, 25 Feb 2017 14:19:19 +0200) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 208.118.235.43 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" Xref: news.gmane.org gmane.emacs.bugs:129784 Archived-At: severity 25863 minor thanks > Date: Sat, 25 Feb 2017 14:19:19 +0200 > From: Eli Zaretskii > Cc: 25863@debbugs.gnu.org > > > (let ((h 16)) > > (switch-to-buffer (generate-new-buffer "temp")) > > (insert-image (create-image (concat (format "P4\n8 %d\n" h) > > (make-string h 127)) > > 'pbm t)) > > (insert ?g) > > (redisplay) > > (delete-char -1)) > > Thanks, I see it now. Looks like a basic deficiency in the design of the Emacs redisplay, and in particular the way screen lines are redrawn when they have variable-height glyphs. Fortunately, this is a fairly rare situation. In the recipe above, it's enough to make a very small change to make the problem go away: (let ((h 16)) (switch-to-buffer (generate-new-buffer "temp")) (insert "x") ;; <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< (insert-image (create-image (concat (format "P4\n8 %d\n" h) (make-string h 127)) 'pbm t)) (insert ?g) (redisplay) (delete-char -1)) Or maybe I'm missing something; ideas are welcome.