git-commit-vandalism/t/t3409-rebase-environ.sh

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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 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 <newren@gmail.com> Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de> Acked-by: Johannes Altmanninger <aclopte@gmail.com> Acked-by: Phillip Wood <phillip.wood123@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 06:36:59 +01:00
#!/bin/sh
test_description='git rebase interactive environment'
built-ins & libs & helpers: add/move destructors, fix leaks Fix various leaks in built-ins, libraries and a test helper here we were missing a call to strbuf_release(), string_list_clear() etc, or were calling them after a potential "return". Comments on individual changes: - builtin/checkout.c: Fix a memory leak that was introduced in [1]. A sibling leak introduced in [2] was recently fixed in [3]. As with [3] we should be using the wt_status_state_free_buffers() API introduced in [4]. - builtin/repack.c: Fix a leak that's been here since this use of "strbuf_release()" was added in a1bbc6c0176 (repack: rewrite the shell script in C, 2013-09-15). We don't use the variable for anything except this loop, so we can instead free it right afterwards. - builtin/rev-parse: Fix a leak that's been here since this code was added in 21d47835386 (Add a parseopt mode to git-rev-parse to bring parse-options to shell scripts., 2007-11-04). - builtin/stash.c: Fix a couple of leaks that have been here since this code was added in d4788af875c (stash: convert create to builtin, 2019-02-25), we strbuf_release()'d only some of the "struct strbuf" we allocated earlier in the function, let's release all of them. - ref-filter.c: Fix a leak in 482c1191869 (gpg-interface: improve interface for parsing tags, 2021-02-11), we don't use the "payload" variable that we ask parse_signature() to populate for us, so let's free it. - t/helper/test-fake-ssh.c: Fix a leak that's been here since this code was added in 3064d5a38c7 (mingw: fix t5601-clone.sh, 2016-01-27). Let's free the "struct strbuf" as soon as we don't need it anymore. 1. c45f0f525de (switch: reject if some operation is in progress, 2019-03-29) 2. 2708ce62d21 (branch: sort detached HEAD based on a flag, 2021-01-07) 3. abcac2e19fa (ref-filter.c: fix a leak in get_head_description, 2022-09-25) 4. 962dd7ebc3e (wt-status: introduce wt_status_state_free_buffers(), 2020-09-27). Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Taylor Blau <me@ttaylorr.com>
2022-11-08 19:17:42 +01:00
TEST_PASSES_SANITIZE_LEAK=true
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 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 <newren@gmail.com> Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de> Acked-by: Johannes Altmanninger <aclopte@gmail.com> Acked-by: Phillip Wood <phillip.wood123@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 06:36:59 +01:00
. ./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