From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-3.1 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id 8AC141F66F for ; Tue, 10 Nov 2020 15:38:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732645AbgKJPis (ORCPT ); Tue, 10 Nov 2020 10:38:48 -0500 Received: from mout.gmx.net ([212.227.17.22]:40453 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732457AbgKJPir (ORCPT ); Tue, 10 Nov 2020 10:38:47 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1605022720; bh=Jk0Z81kTOFRF2epYhMLg1vMdkcI1ForQ2k77aDCsuZ8=; h=X-UI-Sender-Class:Date:From:To:cc:Subject:In-Reply-To:References; b=E4cPhwj6R0epSmH0Z+PopqhXYZWo4cDYxoxNwKB9OA0Jc0+XgEbLrsWVYPL+wQKPp y50NPoS39anboDHqQVASjJm6iAGwZnbmmyTY8NUXAeQOJjBgIbiOaTqyOEg8gMtPef 49hN8FB/uzmQX3TJwO5wdC9cZ7vYXRu3VJ9Gq/fs= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [172.26.25.62] ([213.196.212.205]) by mail.gmx.com (mrgmx104 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MtOGU-1kJCUo2TtO-00urtb; Tue, 10 Nov 2020 16:38:40 +0100 Date: Tue, 10 Nov 2020 16:38:39 +0100 (CET) From: Johannes Schindelin X-X-Sender: virtualbox@gitforwindows.org To: Jinoh Kang cc: Junio C Hamano , git@vger.kernel.org Subject: Re: [PATCH v4] diff: make diff_free_filespec_data accept NULL In-Reply-To: <137f0fc1-fbd9-a62c-bd52-cffd26c364bf@theori.io> Message-ID: References: <137f0fc1-fbd9-a62c-bd52-cffd26c364bf@theori.io> User-Agent: Alpine 2.21.1 (DEB 209 2017-03-23) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Provags-ID: V03:K1:HP6yu1IkV0rVUKRy4HnRIZqFydpsNVh4jSHoWpJmdpIyUVGft3G dhsIHio4UD4b+rF10lr4I1qQW1NrfbRGqxBTd67+JyrK6a+K77Ld6mlMm2fZkDnI7qFdWdp lE5sK3gybc/KP8P31sZiaERkExLOJU9TXC9EMJHHk6iq+fkQm6bIKgH4d+yUcnr3GzKF1ce cMCiTZJsk968VDVLenKXw== X-UI-Out-Filterresults: notjunk:1;V03:K0:kSrqXTUEnsY=:TtS/mcv53cFdayn9TcRTpf I1SspcF6Vzf/zksACrHR07hv0Q5EyJ0a/61PMVk9Jm3Pz+1vvSt93Xq81RGmnoXI7bJlK6Lg5 0G6Ns2rSv5E5xOcs0bHqZkm19RqRnp7DdfzY05ZEFFD1Ic+SuX1rU6pypwHpBielIDI+TMXuw r1uyRcNMe0GPkffq9oIZ/WIqMwm55oAdQdNAN5NN9MMV1iHwpgKci3KYa2HLNmvNhNdED36ca mLt0l6g1BePvWZB9K4z3YINsvSfqhI8IWjes0oS54a46GOLQ6nnhVE0t4xUI1KalOEfT8lhpq ytEX1dUjCbYIsvYFWAPbK5Rn8iYq0LY3FjtCoIWNXtkKuhx/icoZinccswKm/98kK+BY3JOMO Bp6Lik6BFopSJMuP+1aiFz+yGsSG62kOvZEdCkn5vU3uxIwiiXr09rEqh0qmxE52fl+BtyUmI U2RjD7fGNlZOgdgnHxLLOtWg4+JGZc8oiIoz+gP38cRbmdSpdMrHnsGaYsMwQ6m22NED9Ui4D bxKYIwPPfumSu6xaAp94V/6qMRwRxDcR9SOKmO4nhuBPJufY50H5lfofyKdlw2y2NezXsGaBP +acOMKy2BFjDtVO7ymbhgM28TZN9AYPC0H2BWVfJvEYyi6fZfb9D7XUBzAGTA5bZMBnGdVBRS 0YdOX6SkbvVl+oReWxcQEpWXdepYTzjMw3qLpvu9ApVvjlnMtolgP4WgUP911n4GlJN1FyiXj alxlC70mPZHpgO1Bwm0ByGaIYGamCbu1W89sHjvFqH7nWkYHAXtA/WRIkjJsc19Lm/3lK7Yrj yayq25AxpDRbrvf7BFQwNKHUJ35oCzQnofRrR7/9WfueSzijaYZV9tNLOXWIp9mxVzsi3pozV XQtFR/I7XBuw7ngcMQWNo952xhrj/7Blr7gHsDNto= Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Hi Jinoh, On Tue, 10 Nov 2020, Jinoh Kang wrote: > Today, diff_free_filespec_data crashes when passed a NULL pointer. > Commit 3aef54e8b8 ("diff: munmap() file contents before running external > diff") introduced calls to diff_free_filespec_data in run_external_diff, > which may pass NULL pointers. > > Git uses NULL filespecs to indicate unmerged files when merge conflict > resolution is in progress. Fortunately, other code paths bail out early > even before NULL can reach diff_free_filespec_data(); however, difftool > is expected to do a full-blown diff anyway regardless of conflict > status. > > Fix this and prevent any similar bugs in the future by making > `diff_free_filespec_data(NULL)` a no-op. > > Also, add a test case that confirms that running difftool --cached with > unmerged files does not SIGSEGV. > > Signed-off-by: Jinoh Kang > --- > diff.c | 3 +++ > t/t7800-difftool.sh | 23 +++++++++++++++++++++++ > 2 files changed, 26 insertions(+) > > diff --git a/diff.c b/diff.c > index d24f47df99..ace4a1d387 100644 > --- a/diff.c > +++ b/diff.c > @@ -4115,6 +4115,9 @@ void diff_free_filespec_blob(struct diff_filespec = *s) > > void diff_free_filespec_data(struct diff_filespec *s) > { > + if (!s) > + return; > + I had suggested an improvement for this hunk as well as for the test case. Fell through the cracks? Ciao, Dscho > diff_free_filespec_blob(s); > FREE_AND_NULL(s->cnt_data); > } > diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh > index 524f30f7dc..e9391abb54 100755 > --- a/t/t7800-difftool.sh > +++ b/t/t7800-difftool.sh > @@ -728,6 +728,29 @@ test_expect_success 'add -N and difftool -d' ' > git difftool --dir-diff --extcmd ls > ' > > +test_expect_success 'difftool --cached with unmerged files' ' > + test_when_finished git reset --hard && > + echo base >file && > + git add file && > + git commit -m base && > + git checkout -B conflict-a && > + git checkout -B conflict-b && > + git checkout conflict-a && > + echo conflict-a >>file && > + git add file && > + git commit -m conflict-a && > + git checkout conflict-b && > + echo conflict-b >>file && > + git add file && > + git commit -m conflict-b && > + git checkout master && > + git merge conflict-a && > + test_must_fail git merge conflict-b && > + : >expect && > + git difftool --cached --no-prompt >actual && > + test_cmp expect actual > +' > + > test_expect_success 'outside worktree' ' > echo 1 >1 && > echo 2 >2 && > -- > 2.26.2 >