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#8512: possibly uninitialized variable in x_produce_glyphs Date: Sun, 17 Apr 2011 00:24:32 +0300 Message-ID: <831v11q48f.fsf@gnu.org> References: <4DA9F0B4.1090204@cs.ucla.edu> Reply-To: Eli Zaretskii NNTP-Posting-Host: lo.gmane.org X-Trace: dough.gmane.org 1302989854 27929 80.91.229.12 (16 Apr 2011 21:37:34 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sat, 16 Apr 2011 21:37:34 +0000 (UTC) Cc: 8512@debbugs.gnu.org To: Paul Eggert Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Sat Apr 16 23:37:30 2011 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1QBDBJ-00066D-T2 for geb-bug-gnu-emacs@m.gmane.org; Sat, 16 Apr 2011 23:37:30 +0200 Original-Received: from localhost ([::1]:39618 helo=lists2.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QBDBJ-0008CQ-FE for geb-bug-gnu-emacs@m.gmane.org; Sat, 16 Apr 2011 17:37:29 -0400 Original-Received: from eggs.gnu.org ([140.186.70.92]:58048) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QBDBG-00087O-75 for bug-gnu-emacs@gnu.org; Sat, 16 Apr 2011 17:37:26 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QBDBE-0006Ut-TT for bug-gnu-emacs@gnu.org; Sat, 16 Apr 2011 17:37:26 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:55027) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QBDBE-0006Up-QW for bug-gnu-emacs@gnu.org; Sat, 16 Apr 2011 17:37:24 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.69) (envelope-from ) id 1QBD1C-0001UG-1w; Sat, 16 Apr 2011 17:27:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-To: owner@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 16 Apr 2011 21:27:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 8512 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 8512-submit@debbugs.gnu.org id=B8512.13029891725659 (code B ref 8512); Sat, 16 Apr 2011 21:27:02 +0000 Original-Received: (at 8512) by debbugs.gnu.org; 16 Apr 2011 21:26:12 +0000 Original-Received: from localhost ([127.0.0.1] helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1QBD0O-0001TE-38 for submit@debbugs.gnu.org; Sat, 16 Apr 2011 17:26:12 -0400 Original-Received: from mtaout22.012.net.il ([80.179.55.172]) by debbugs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1QBD0L-0001Sz-Go for 8512@debbugs.gnu.org; Sat, 16 Apr 2011 17:26:10 -0400 Original-Received: from conversion-daemon.a-mtaout22.012.net.il by a-mtaout22.012.net.il (HyperSendmail v2007.08) id <0LJR00400K7BG400@a-mtaout22.012.net.il> for 8512@debbugs.gnu.org; Sun, 17 Apr 2011 00:24:33 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([77.124.96.168]) by a-mtaout22.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0LJR003KBKSVWWF0@a-mtaout22.012.net.il>; Sun, 17 Apr 2011 00:24:33 +0300 (IDT) In-reply-to: <4DA9F0B4.1090204@cs.ucla.edu> X-012-Sender: halo1@inter.net.il X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.11 Precedence: list Resent-Date: Sat, 16 Apr 2011 17:27:02 -0400 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) 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:45842 Archived-At: > Date: Sat, 16 Apr 2011 12:40:36 -0700 > From: Paul Eggert > > In the Emacs trunk, GCC 3.4.3 on Solaris 10 warns about a possibly uninitialized > variable in x_produce_glyphs, and it's not clear to me that this diagnostic is > wrong. The function assumes that cmp->glyph_len > 0, but a quick look through the > rest of Emacs suggests that it's possible that it's zero. To play it safe > until someone with more expertise about glyphs can look at the problem, I plan > to install this patch: > > --- src/xdisp.c 2011-04-16 01:54:37 +0000 > +++ src/xdisp.c 2011-04-16 19:24:11 +0000 > @@ -22712,7 +22712,7 @@ x_produce_glyphs (struct it *it) > int lbearing, rbearing; > int i, width, ascent, descent; > int left_padded = 0, right_padded = 0; > - int c; > + int c = 0; /* FIXME: Is 0 right here, when cmp->glyph_len == 0? */ I don't think it matters how you initialize c here, because cmp->glyph_len can never be zero there. However, using c=0 here is not right, I think; I would use a printable character, like ' ' or something, so that get_char_face_and_encoding gets a real character to play with.