From patchwork Thu Aug 13 05:25:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff King X-Patchwork-Id: 11711689 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F0B20739 for ; Thu, 13 Aug 2020 05:25:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DD08020715 for ; Thu, 13 Aug 2020 05:25:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725978AbgHMFZc (ORCPT ); Thu, 13 Aug 2020 01:25:32 -0400 Received: from cloud.peff.net ([104.130.231.41]:57360 "EHLO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725891AbgHMFZc (ORCPT ); Thu, 13 Aug 2020 01:25:32 -0400 Received: (qmail 15561 invoked by uid 109); 13 Aug 2020 05:25:32 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with ESMTP; Thu, 13 Aug 2020 05:25:32 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 10619 invoked by uid 111); 13 Aug 2020 05:25:31 -0000 Received: from coredump.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.2) by peff.net (qpsmtpd/0.94) with (TLS_AES_256_GCM_SHA384 encrypted) ESMTPS; Thu, 13 Aug 2020 01:25:31 -0400 Authentication-Results: peff.net; auth=none Date: Thu, 13 Aug 2020 01:25:31 -0400 From: Jeff King To: Junio C Hamano Cc: Barret Rhoden , Nuthan Munaiah , git@vger.kernel.org Subject: [PATCH 3/3] blame: only coalesce lines that are adjacent in result Message-ID: <20200813052531.GC2514880@coredump.intra.peff.net> References: <20200813052054.GA1962792@coredump.intra.peff.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200813052054.GA1962792@coredump.intra.peff.net> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org After blame has finished but before we produce any output, we coalesce groups of lines that were adjacent in the original suspect (which may have been split apart by lines in intermediate commits which went away). However, this can cause incorrect output if the lines are not also adjacent in the result. For instance, the case in t8003 has: ABC DEF which becomes ABC SPLIT DEF Blaming only lines 1 and 3 in the result yields two blame groups (one for each line) that were adjacent in the original. That's enough for us to coalesce them into a single group, but that loses information: our output routines assume they're adjacent in the result as well, and we output: 1) ABC 2) SPLIT This is nonsense for two reasons: - we were asked about line 3, not line 2; we should not output the SPLIT line at all - commit did not touch the SPLIT line at all! We found the correct blame for line 3, but the bug is actually in the output stage, which is showing the wrong line number and content from the final file. We can fix this by only coalescing when both the suspect and result lines are adjacent. That fixes this bug, but keeps coalescing in cases where want it (e.g., the existing test in t8003 where SPLIT goes away, and the lines really are adjacent in the result). Reported-by: Nuthan Munaiah Signed-off-by: Jeff King --- blame.c | 1 + t/t8003-blame-corner-cases.sh | 9 +++++++++ 2 files changed, 10 insertions(+) diff --git a/blame.c b/blame.c index 82fa16d658..1be1cd82a2 100644 --- a/blame.c +++ b/blame.c @@ -1184,6 +1184,7 @@ void blame_coalesce(struct blame_scoreboard *sb) for (ent = sb->ent; ent && (next = ent->next); ent = next) { if (ent->suspect == next->suspect && ent->s_lno + ent->num_lines == next->s_lno && + ent->lno + ent->num_lines == next->lno && ent->ignored == next->ignored && ent->unblamable == next->unblamable) { ent->num_lines += next->num_lines; diff --git a/t/t8003-blame-corner-cases.sh b/t/t8003-blame-corner-cases.sh index 7f39a84289..ba8013b002 100755 --- a/t/t8003-blame-corner-cases.sh +++ b/t/t8003-blame-corner-cases.sh @@ -310,4 +310,13 @@ test_expect_success 'blame coalesce' ' test_cmp expect actual ' +test_expect_success 'blame does not coalesce non-adjacent result lines' ' + cat >expect <<-EOF && + $orig 1) ABC + $orig 3) DEF + EOF + git blame --no-abbrev -s -L1,1 -L3,3 $split giraffe >actual && + test_cmp expect actual +' + test_done