From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Jashank Jeremy Newsgroups: gmane.emacs.devel Subject: Re: master 242a4b49cb: Minor cleanups to X drag-and-drop code Date: Sun, 22 May 2022 16:56:15 +1000 Message-ID: <87v8tyf434.wl-jashank@rulingia.com.au> Mime-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: multipart/signed; boundary="pgp-sign-Multipart_Sun_May_22_16:56:07_2022-1"; micalg=pgp-sha256; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="39761"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?ISO-8859-4?Q?Goj=F2?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.0.50 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) To: Po Lu , Emacs development list Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun May 22 09:27:35 2022 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nsfzx-000A7U-DG for ged-emacs-devel@m.gmane-mx.org; Sun, 22 May 2022 09:27:35 +0200 Original-Received: from localhost ([::1]:43464 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nsfzw-0002i7-6x for ged-emacs-devel@m.gmane-mx.org; Sun, 22 May 2022 03:27:32 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:52732) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nsfVk-0002GL-6a for emacs-devel@gnu.org; Sun, 22 May 2022 02:56:21 -0400 Original-Received: from emeralfel.rulingia.com.au ([52.64.96.81]:43653 helo=fort.rulingia.com.au) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nsfVi-0006rY-28 for emacs-devel@gnu.org; Sun, 22 May 2022 02:56:19 -0400 Original-Received: from alyzon.rulingia.com.au (60-242-28-107.static.tpgi.com.au [60.242.28.107]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by fort.rulingia.com.au (Postfix) with ESMTPSA id 8B1B7211100; Sun, 22 May 2022 16:56:15 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rulingia.com.au; s=mail; t=1653202575; bh=2ebUDr1YjfUeMAWqkr7hpZDY/3+XW0IRZU48nin1QBI=; h=Date:From:To:Subject; b=WcfDFiurAmcvmlmDsli6GQy5LH+x/I2cLKQ2dg7brHtWVkJggILqDNlRbnFmSNNwg PwXA5MUKPJEwpVOyyRR9t6n2C1TzbZrS6EWrRmMmRKQ1TjncCF+otlCc1TWqHVpOgX Q/uTXByQam7hd/8vh4oY2554WmySsNfx/j+gwVjE= Original-Received: from lisbon.rulingia.com.au (lisbon.rulingia.com.au [192.168.5.76]) by alyzon.rulingia.com.au (Postfix) with ESMTPA id 4A961310B56; Sun, 22 May 2022 16:56:15 +1000 (AEST) Received-SPF: pass client-ip=52.64.96.81; envelope-from=jashank@rulingia.com.au; helo=fort.rulingia.com.au X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Sun, 22 May 2022 03:26:09 -0400 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:290074 Archived-At: --pgp-sign-Multipart_Sun_May_22_16:56:07_2022-1 Content-Type: text/plain; charset=US-ASCII > diff --git a/src/xterm.c b/src/xterm.c > index a8745894eb2..a3b7c4ac257 100644 > --- a/src/xterm.c > +++ b/src/xterm.c > [...] > @@ -1977,6 +2012,9 @@ xm_read_drag_receiver_info (struct x_display_info *dpyinfo, > rec->byteorder = XM_BYTE_ORDER_CUR_FIRST; > } > > + if (data[1] > XM_DRAG_PROTOCOL_VERSION) > + rc = 0; > + > if (tmp_data) > XFree (tmp_data); Whilst chasing down the build failure against e465ea816d, I observed some compiler warnings related to this patch: .../emacs/src/src/xterm.c:1994:7: warning: variable 'data' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (rc) ^~ .../emacs/src/src/xterm.c:2016:7: note: uninitialized use occurs here if (data[1] > XM_DRAG_PROTOCOL_VERSION) ^~~~ .../emacs/src/src/xterm.c:1994:3: note: remove the 'if' if its condition is always true if (rc) ^~~~~~~ .../emacs/src/src/xterm.c:1977:16: note: initialize the variable 'data' to silence this warning uint8_t *data; ^ = NULL This looks like a plausible issue --- XGetWindowProperty looks to be fallible, and in the event it fails we're potentially dereferencing an uninitialised value. I suspect the check introduced in this commit should be within the immediately preceding region; however, I do not know what the implications of such a change would be, and thus won't concretely suggest one. ~jashank --pgp-sign-Multipart_Sun_May_22_16:56:07_2022-1 Content-Type: application/pgp-signature Content-Transfer-Encoding: 7bit Content-Description: OpenPGP Digital Signature -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEERaoh5i4JiQ9obEzcWzDW4sQdSv0FAmKJ3ocACgkQWzDW4sQd Sv1/fg/+OCl0W4xw2GMH5LiwfUIyW1BsxW2jmd2CyFrlaSVGzJyHVK8M6pPz9z9P sj/76UO6BFIoH9iW7figdKrKGdIR9SsUJ3zrSFmqZdtiXZRTq6BJADJQ+38lyjuk /GyINpJTF7Bs/0HJRi/hng3DfoNrv7ln7JrHJXB9KMcFnJd8/OK1T9DnM2FSExTK uXxCS55To1dyuFVkvyNGryHJQFm47ljXpdKBzSIMwCOzpUta8J3WuRjG1Fq9GvEx JsfswxPJOW7J+cDpABIKcY5P+uch1vqpcfvzFWU7IHZTZ+Q1IfonmyfF//xMm/2G mMrE4HnXUwI/VDOaqqWdTStbY/4z+b53H5vjgO0wr4p4hMCUKavqBlcLjG5OnRMH bGzrAIbzZwdQwI78vl8D/ITIXGwYYhoGsRqlJ7MxkarB9NWoAmYqL4kcwWIlLpWG d/zYLeIsAbzKR3yn5c5/TyrUFfBzsFHqNUKsLgvvos0EO44sL43N9fq45yWIm2ue HE63BYHNyhDQffHCtOLHBfHEBXswmZxEDs3fCme2EcYwrJjMkEOyaBoLiHGCdlsT 65P4Brc9C7mEH7TKvu6aPwbXHGuwDkNFnTvbC6Hr1mbkWE1LVvL1Lq8bcGl19U8t 7KtcJFdggdwRiSHUcmf3W/z5zpxFFmgTU3PEsZf0w4uZ/h4TGU8= =rWim -----END PGP SIGNATURE----- --pgp-sign-Multipart_Sun_May_22_16:56:07_2022-1--