The five new tests added to 't9300-fast-import.sh' in 30e215a65c
(fast-import: checkpoint: dump branches/tags/marks even if
object_count==0, 2017-09-28), all with the prefix "V:" in their test
description, run 'git fast-import' in the background and then 'kill'
it as part of a 'test_when_finished' cleanup command. When this test
script is executed with Bash, some or even all of these tests tend to
pollute the test script's stderr, and messages about terminated
processes end up on the terminal:
$ bash ./t9300-fast-import.sh
<... snip ...>
ok 179 - V: checkpoint helper does not get stuck with extra output
/<...>/test-lib-functions.sh: line 388: 28383 Terminated git fast-import $options 0<&8 1>&9
ok 180 - V: checkpoint updates refs after reset
./t9300-fast-import.sh: line 3210: 28401 Terminated git fast-import $options 0<&8 1>&9
ok 181 - V: checkpoint updates refs and marks after commit
ok 182 - V: checkpoint updates refs and marks after commit (no new objects)
./test-lib.sh: line 634: line 3250: 28485 Terminated git fast-import $options 0<&8 1>&9
ok 183 - V: checkpoint updates tags after tag
./t9300-fast-import.sh: line 3264: 28510 Terminated git fast-import $options 0<&8 1>&9
After a background child process terminates, its parent Bash process
always outputs a message like those above to stderr, even when in
non-interactive mode.
But how do some of these messages end up on the test script's stderr,
why don't we get them from all five tests, and why do they come from
different file/line locations? Well, after sending the TERM signal to
the background child process, it takes a little while until that
process receives the signal and terminates, and then it takes another
while until the parent process notices it. During this time the
parent Bash process is continuing execution, and by the time it
notices that its child terminated it might have already left
'test_eval_inner_' and its stderr is not redirected to /dev/null
anymore. That's why such a message can appear on the test script's
stderr, while other times, when the child terminates fast and/or the
parent shell is slow enough, the message ends up in /dev/null, just
like any other output of the test does. Bash always adds the file
name and line number of the code location it was about to execute when
it notices the termination of its child process as a prefix to that
message, hence the varying and sometimes totally unrelated location
prefixes in those messages (e.g. line 388 in 'test-lib-functions.sh'
is 'test_verify_prereq', and I saw such a message pointing to
'say_color' as well).
Prevent these messages from appearing on the test script's stderr by
'wait'-ing on the pid of the background 'git fast-import' process
after sending it the TERM signal. This ensures that the executing
shell's stderr is still redirected when the shell notices the
termination of its child process in the background, and that these
messages get a consistent file/line location prefix.
Note that this is not an issue when the test script is run with Bash
and '-v', because then these messages are supposed to go to the test
script's stderr anyway, and indeed all of them do; though the
sometimes seemingly random file/line prefixes could be confusing
still. Similarly, it's not an issue with Bash and '--verbose-log'
either, because then all messages go to the log file as they should.
Finally, it's not an issue with some other shells (I tried dash, ksh,
ksh93 and mksh) even without any of the verbose options, because they
don't print messages like these in non-interactive mode in the first
place.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git - fast, scalable, distributed revision control system
Git is a fast, scalable, distributed revision control system with an
unusually rich command set that provides both high-level operations
and full access to internals.
Git is an Open Source project covered by the GNU General Public
License version 2 (some parts of it are under different licenses,
compatible with the GPLv2). It was originally written by Linus
Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from https://git-scm.com/
including full documentation and Git related tools.
See Documentation/gittutorial.txt to get started, then see
Documentation/giteveryday.txt for a useful minimum set of commands, and
Documentation/git-.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with man gittutorial or git help tutorial, and the
documentation of each command with man git-<commandname> or git help <commandname>.
CVS users may also want to read Documentation/gitcvs-migration.txt
(man gitcvs-migration or git help cvs-migration if git is
installed).
The maintainer frequently sends the "What's cooking" reports that
list the current status of various development topics to the mailing
list. The discussion following them give a good reference for
project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very
first version. He described the tool as "the stupid content tracker"
and the name as (depending on your mood):
random three-letter combination that is pronounceable, and not
actually used by any common UNIX command. The fact that it is a
mispronunciation of "get" may or may not be relevant.
stupid. contemptible and despicable. simple. Take your pick from the
dictionary of slang.
"global information tracker": you're in a good mood, and it actually
works for you. Angels sing, and a light suddenly fills the room.
"goddamn idiotic truckload of sh*t": when it breaks
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