From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id C6ED01FD99 for ; Sat, 13 Aug 2016 11:30:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752262AbcHMLah (ORCPT ); Sat, 13 Aug 2016 07:30:37 -0400 Received: from mta01.prd.rdg.aluminati.org ([94.76.243.214]:58316 "EHLO mta01.prd.rdg.aluminati.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752180AbcHMLah (ORCPT ); Sat, 13 Aug 2016 07:30:37 -0400 Received: from mta01.prd.rdg.aluminati.org (localhost [127.0.0.1]) by mta.aluminati.local (Postfix) with ESMTP id 23D62C4702; Sat, 13 Aug 2016 12:30:35 +0100 (BST) Received: from localhost (localhost [127.0.0.1]) by mta01.prd.rdg.aluminati.org (Postfix) with ESMTP id 1A94520CD8; Sat, 13 Aug 2016 12:30:35 +0100 (BST) X-Quarantine-ID: <2OsYIaR26nYJ> X-Virus-Scanned: Debian amavisd-new at mta01.prd.rdg.aluminati.org Received: from mta.aluminati.local ([127.0.0.1]) by localhost (mta01.prd.rdg.aluminati.org [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 2OsYIaR26nYJ; Sat, 13 Aug 2016 12:30:32 +0100 (BST) Received: from john.keeping.me.uk (unknown [10.2.0.10]) by mta01.prd.rdg.aluminati.org (Postfix) with ESMTPSA id 6EF916212F; Sat, 13 Aug 2016 12:30:29 +0100 (BST) Date: Sat, 13 Aug 2016 12:30:28 +0100 From: John Keeping To: "Tom Tanner (BLOOMBERG/ LONDON)" , David Aguilar Cc: git@vger.kernel.org Subject: [PATCH] difftool: always honor "command not found" exit code Message-ID: <20160813113028.uwedje6fzuc3cuzr@john.keeping.me.uk> References: <57AD772501C207A400390148_0_15304@p057> <20160813103639.mxscvfyztee4hbvh@john.keeping.me.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160813103639.mxscvfyztee4hbvh@john.keeping.me.uk> User-Agent: Mutt/1.6.2 (2016-06-11) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org At the moment difftool's "trust exit code" logic always suppresses the exit status of the diff utility we invoke. This is useful because we don't want to exit just because diff returned "1" because the files differ, but it's confusing if the shell returns an error because the selected diff utility is not found. POSIX specifies 127 as the exit status for "command not found" and 126 for "command found but is not executable" [1] and at least bash and dash follow this specification, while diff utilities generally use "1" for the exit status we want to ignore. Handle 126 and 127 as special values, assuming that they always mean that the command could not be executed. [1] http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_08_02 Signed-off-by: John Keeping --- On Sat, Aug 13, 2016 at 11:36:39AM +0100, John Keeping wrote: > It would be nice if there was a way to differentiate between complete > failure and just the diff tool exiting with a non-zero return status > because the files differ, but I'm not sure whether we can do that > reliably. POSIX uses 127 and 126 as errors that mean the command didn't > run [1] so it may be sensible to to treat those as special values. Something like this perhaps? I think this is probably safe, but it's always possible that some diff utility does use 126 or 127 as a "normal" exit status. I'm not sure what we can do about that other than add a "really, really don't trust the exit status" option! git-difftool--helper.sh | 18 ++++++++++++++---- t/t7800-difftool.sh | 6 ++++++ 2 files changed, 20 insertions(+), 4 deletions(-) diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh index 84d6cc0..68877d4 100755 --- a/git-difftool--helper.sh +++ b/git-difftool--helper.sh @@ -86,11 +86,21 @@ else do launch_merge_tool "$1" "$2" "$5" status=$? - if test "$status" != 0 && - test "$GIT_DIFFTOOL_TRUST_EXIT_CODE" = true - then + case "$status" in + 0) + : OK + ;; + 126|127) + # Command not found or not executable exit $status - fi + ;; + *) + if test "$GIT_DIFFTOOL_TRUST_EXIT_CODE" = true + then + exit $status + fi + ;; + esac shift 7 done fi diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh index 2974900..70a2de4 100755 --- a/t/t7800-difftool.sh +++ b/t/t7800-difftool.sh @@ -124,6 +124,12 @@ test_expect_success PERL 'difftool stops on error with --trust-exit-code' ' test_cmp expect actual ' +test_expect_success PERL 'difftool honors exit status if command not found' ' + test_config difftool.nonexistent.cmd i-dont-exist && + test_config difftool.trustExitCode false && + test_must_fail git difftool -y -t nonexistent branch +' + test_expect_success PERL 'difftool honors --gui' ' difftool_test_setup && test_config merge.tool bogus-tool && -- 2.9.2.639.g855ae9f