diff options
author | Elijah Newren <newren@gmail.com> | 2021-12-04 08:36:59 +0300 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2021-12-05 10:41:05 +0300 |
commit | 434e0636db102cd89292ea28e8e947fa6e790b23 (patch) | |
tree | 194852b0130b232a2d6c4fc922f6fad1784c3590 /t | |
parent | e9d7761bb94f20acc98824275e317fa82436c25d (diff) |
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>
Diffstat (limited to 't')
-rwxr-xr-x | t/t3409-rebase-environ.sh | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/t/t3409-rebase-environ.sh b/t/t3409-rebase-environ.sh new file mode 100755 index 0000000000..83ffb39d9f --- /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 |