From patchwork Tue Nov 16 05:53:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elijah Newren X-Patchwork-Id: 12621397 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 45420C433EF for ; Tue, 16 Nov 2021 06:01:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11827613D0 for ; Tue, 16 Nov 2021 06:01:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239597AbhKPGEb (ORCPT ); Tue, 16 Nov 2021 01:04:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238565AbhKPGEF (ORCPT ); Tue, 16 Nov 2021 01:04:05 -0500 Received: from mail-wm1-x32e.google.com (mail-wm1-x32e.google.com [IPv6:2a00:1450:4864:20::32e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF268C04A426 for ; Mon, 15 Nov 2021 21:53:09 -0800 (PST) Received: by mail-wm1-x32e.google.com with SMTP id c71-20020a1c9a4a000000b0032cdcc8cbafso1448051wme.3 for ; Mon, 15 Nov 2021 21:53:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=jxkzFtdgBu0nPvc6JuDMXEaL6epvu0ptKDMohNM3WF0=; b=XelA1V1zShPTkqJQHaM7geXnnAIrNaV4hsucxemOgpY5i1LhLR/QPT+gH028GV27/x SZOWOw6RXsZt8uIlb8/RMKagA12El4xR9Ey9hVKiwxGXLxTo87766lS3fydVCAfauPXJ RWZcThKl4BZfN3cqOIxlMLJfo7osjvK04NpOXyh70yAPn1pueHxLTg1ybVJUCi3CD6lU MjVBQ6AS8zdY0MXutDaHX6wBmyntIS5A31I/raTHGd7STsdMiTWdxShtnd1/LnYPVACD LYUZcQZiyUAN6GnvFCUpkdJwbMb6KzLnL9oo4Xv0aubtwM1nHaR6bOsEkt0aJcq/2awd UP2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=jxkzFtdgBu0nPvc6JuDMXEaL6epvu0ptKDMohNM3WF0=; b=ERVTyoU56VoL9pt8dOmKud1eZk7JhuKO1G7N6nlLhJ8pCN+Qky7qmuur4UcS3FEE5e gYyL73zE5038+DR68UzBSH/Fs+te8NIIJx+hxJe4g5nEJrpTE13/OrOVmFaPXPnbHzDp BTBVWlMvlo8RrmlNl2Ohdl1j8dbm+Bf/ifv4Dv3g1eFLJ3WZAkenlyoVk2lhJ+32Axj7 OL210G19NFqLwkAy69pJu8XMmMIZGsFfgYZb8jbzPavKjQqiZtku7PqqKWWFbMOjnlsR ieRIbJSnxASRJCr9juy6O9ilGHOqHdu+/eOmfU4fNLeKWiIVLdANyhakituxL297Pokk qQAw== X-Gm-Message-State: AOAM532o+D01PfTuWVGcHC9R9r7SD3HABOU3MmCH7YDUXLK48QvWK7/v NuoEc0NIi843W48SsO0IxZlod8fXLwc= X-Google-Smtp-Source: ABdhPJxVLgo3ayAljL4H18sia8h01W571r2h3kXl5ZeR3Zi9RWD++jt5gGumfJh6cW7rlUfBxv5SdQ== X-Received: by 2002:a7b:c207:: with SMTP id x7mr66777577wmi.108.1637041988041; Mon, 15 Nov 2021 21:53:08 -0800 (PST) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id d9sm16261524wre.52.2021.11.15.21.53.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Nov 2021 21:53:07 -0800 (PST) Message-Id: In-Reply-To: References: Date: Tue, 16 Nov 2021 05:53:06 +0000 Subject: [PATCH v2] sequencer: do not export GIT_DIR and GIT_WORK_TREE for 'exec' Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: Johannes Schindelin , Johannes Altmanninger , Elijah Newren , Elijah Newren Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Elijah Newren From: Elijah Newren Commands executed from `git rebase --exec` can give different behavior from within that environment than they would outside of it, due to the fact that sequencer.c exports both GIT_DIR and GIT_WORK_TREE. For example, if the relevant script calls something like git -C ../otherdir log --format=%H --no-walk the user may be surprised to find that the command above does not show a commit hash from ../otherdir, because $GIT_DIR prevents automatic gitdir detection and makes the -C option useless. This is a regression in behavior from the original legacy implemented-in-shell rebase. It is perhaps rare for it to cause problems in practice, especially since most small problems that were caused by this area of bugs has been fixed-up in the past in a way that masked the particular bug observed without fixing the real underlying problem. An explanation of how we arrived at the current situation is perhaps merited. The setting of GIT_DIR and GIT_WORK_TREE done by sequencer.c arose from a sequence of historical accidents: * When rebase was implemented as a shell command, it would call git-sh-setup, which among other things would set GIT_DIR -- but not export it. This meant that when rebase --exec commands were run via /bin/sh -c "$COMMAND" they would not inherit the GIT_DIR setting. The fact that GIT_DIR was not set in the run $COMMAND is the behavior we'd like to restore. * When the rebase--helper builtin was introduced to allow incrementally replacing shell with C code, we had an implementation that was half shell, half C. In particular, commit 18633e1a22 ("rebase -i: use the rebase--helper builtin", 2017-02-09) added calls to exec git rebase--helper ... which caused rebase--helper to inherit the GIT_DIR environment variable from the shell. git's setup would change the environment variable from an absolute path to a relative one (".git"), but would leave it set. This meant that when rebase --exec commands were run via run_command_v_opt(...) they would inherit the GIT_DIR setting. * In commit 09d7b6c6fa ("sequencer: pass absolute GIT_DIR to exec commands", 2017-10-31), it was noted that the GIT_DIR caused problems with some commands; e.g. git rebase --exec 'cd subdir && git describe' ... would have GIT_DIR=.git which was invalid due to the change to the subdirectory. Instead of questioning why GIT_DIR was set, that commit instead made sequencer change GIT_DIR to be an absolute path and explicitly export it via argv_array_pushf(&child_env, "GIT_DIR=%s", absolute_path(get_git_dir())); run_command_v_opt_cd_env(..., child_env.argv) * In commit ab5e67d751 ("sequencer: pass absolute GIT_WORK_TREE to exec commands", 2018-07-14), it was noted that when GIT_DIR is set but GIT_WORK_TREE is not, that we do not discover GIT_WORK_TREE but just assume it is '.'. That is incorrect if trying to run commands from a subdirectory. However, rather than question why GIT_DIR was set, that commit instead also added GIT_WORK_TREE to the list of things to export. Each of the above problems would have been fixed automatically when git-rebase became a full builtin, had it not been for the fact that sequencer.c started exporting GIT_DIR and GIT_WORK_TREE in the interim. Stop exporting them now. Signed-off-by: Elijah Newren Acked-by: Johannes Schindelin --- sequencer: fix environment that 'exec' commands run under Changes since v1: * Fix wording in multiple locations pointed out by Johannes Altmanninger Note that Johaness Altmanninger also suggested some additional GIT_DIR/GIT_WORK_TREE and --git-dir/--work-tree testcases, but since those change the current working directory to the work tree so that GIT_WORK_TREE ends up being '.' in every case, I think it's straying a bit from the point of the test. If other feel strongly, I can add them in. Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1134%2Fnewren%2Ffix-rebase-exec-environ-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1134/newren/fix-rebase-exec-environ-v2 Pull-Request: https://github.com/git/git/pull/1134 Range-diff vs v1: 1: 12713c83705 ! 1: c647c45375a sequencer: fix environment that 'exec' commands run under @@ Metadata Author: Elijah Newren ## Commit message ## - sequencer: fix environment that 'exec' commands run under + sequencer: do not export GIT_DIR and GIT_WORK_TREE for 'exec' Commands executed from `git rebase --exec` can give different behavior from within that environment than they would outside of it, due to the @@ Commit message masked the particular bug observed without fixing the real underlying problem. - How we arrived at the current situation is perhaps merited. The setting - of GIT_DIR and GIT_WORK_TREE done by sequencer.c arose from a sequence - of historical accidents: + An explanation of how we arrived at the current situation is perhaps + merited. The setting of GIT_DIR and GIT_WORK_TREE done by sequencer.c + arose from a sequence of historical accidents: * When rebase was implemented as a shell command, it would call git-sh-setup, which among other things would set GIT_DIR -- but not @@ Commit message was not set in the run $COMMAND is the behavior we'd like to restore. * When the rebase--helper builtin was introduced to allow incrementally - replacing shell with C code, we were in an implementation that was - half shell, half C. In particular, commit 18633e1a22 ("rebase -i: use - the rebase--helper builtin", 2017-02-09) added calls to + replacing shell with C code, we had an implementation that was half + shell, half C. In particular, commit 18633e1a22 ("rebase -i: use the + rebase--helper builtin", 2017-02-09) added calls to exec git rebase--helper ... which caused rebase--helper to inherit the GIT_DIR environment variable from the shell. git's setup would change the environment @@ Commit message export. Each of the above problems would have been fixed automatically when - git-rebase become a full builtin, had it not been for the fact that + git-rebase became a full builtin, had it not been for the fact that sequencer.c started exporting GIT_DIR and GIT_WORK_TREE in the interim. Stop exporting them now. sequencer.c | 9 +-------- t/t3409-rebase-environ.sh | 23 +++++++++++++++++++++++ 2 files changed, 24 insertions(+), 8 deletions(-) create mode 100755 t/t3409-rebase-environ.sh base-commit: 88d915a634b449147855041d44875322de2b286d diff --git a/sequencer.c b/sequencer.c index ea96837cde3..9afdbe3e3d1 100644 --- a/sequencer.c +++ b/sequencer.c @@ -3495,17 +3495,12 @@ static int error_failed_squash(struct repository *r, static int do_exec(struct repository *r, const char *command_line) { - struct strvec child_env = STRVEC_INIT; const char *child_argv[] = { NULL, NULL }; int dirty, status; fprintf(stderr, _("Executing: %s\n"), command_line); child_argv[0] = command_line; - strvec_pushf(&child_env, "GIT_DIR=%s", absolute_path(get_git_dir())); - strvec_pushf(&child_env, "GIT_WORK_TREE=%s", - absolute_path(get_git_work_tree())); - status = run_command_v_opt_cd_env(child_argv, RUN_USING_SHELL, NULL, - child_env.v); + status = run_command_v_opt(child_argv, RUN_USING_SHELL); /* force re-reading of the cache */ if (discard_index(r->index) < 0 || repo_read_index(r) < 0) @@ -3535,8 +3530,6 @@ static int do_exec(struct repository *r, const char *command_line) status = 1; } - strvec_clear(&child_env); - return status; } diff --git a/t/t3409-rebase-environ.sh b/t/t3409-rebase-environ.sh new file mode 100755 index 00000000000..83ffb39d9ff --- /dev/null +++ b/t/t3409-rebase-environ.sh @@ -0,0 +1,23 @@ +#!/bin/sh + +test_description='git rebase interactive environment' + +. ./test-lib.sh + +test_expect_success 'setup' ' + test_commit one && + test_commit two && + test_commit three +' + +test_expect_success 'rebase --exec does not muck with GIT_DIR' ' + git rebase --exec "printf %s \$GIT_DIR >environ" HEAD~1 && + test_must_be_empty environ +' + +test_expect_success 'rebase --exec does not muck with GIT_WORK_TREE' ' + git rebase --exec "printf %s \$GIT_WORK_TREE >environ" HEAD~1 && + test_must_be_empty environ +' + +test_done