This (morally) reverts commit d280f68313,
which added some tests that are a pain to maintain and are not likely
to find bugs in git.
Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Jeff King <peff@peff.net>
t0081 creates several background processes that write to a fifo and
then go to sleep for a while (so the reader of the fifo does not see
EOF).
Each background process is made in a curly-braced block in the shell,
and after we are done reading from the fifo, we use "kill $!" to kill
it off.
For a simple, single-command process, this works reliably and kills
the child sleep process. But for more complex commands like
"make_some_output && sleep", the results are less predictable. When
executing under bash, we end up with a subshell that gets killed by
the $! but leaves the sleep process still alive.
This is bad not only for process hygeine (we are leaving random sleep
processes to expire after a while), but also interacts badly with the
"prove" command. When prove executes a test, it does not realize the
test is done when it sees SIGCHLD, but rather waits until the test's
stdout pipe is closed. The orphaned sleep process may keep that pipe
open via test-lib's file descriptor 5, causing prove to hang for 100
seconds.
The solution is to explicitly use a subshell and to exec the final
sleep process, so that when we "kill $!" we get the process id of the
sleep process.
[jn: original patch by Jeff had some additional bits:
1. Wrap the "kill" in a test_when_finished, since we want
to clean up the process whether the test succeeds or not.
2. The "kill" is part of our && chain for test success. It
probably won't fail, but it can if the process has
expired before we manage to kill it. So let's mark it
as OK to fail.
I'm postponing that for now.]
Reported-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
All previous users of buffer_read_string have already been converted
to use the more intuitive buffer_read_binary, so remove the old API to
avoid some confusion.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
buffer_read_string works well for non line-oriented input except for
one problem: it does not tell the caller how many bytes were actually
written. This means that unless one is very careful about checking
for errors (and eof) the calling program cannot tell the difference
between the string "foo" followed by an early end of file and the
string "foo\0bar\0baz".
So introduce a variant that reports the length, too, a thinner wrapper
around strbuf_fread. Its result is written to a strbuf so the caller
does not need to keep track of the number of bytes read.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
POSIX makes the behavior of read(2) from a pipe fairly clear: a read
from an empty pipe will block until there is data available and any
other read will not block, prefering to return a partial result.
Likewise, fread(3) and fgets(3) are clearly specified to act as
though implemented by calling fgetc(3) in a simple loop. But the
buffering behavior of fgetc is less clear.
Luckily, no sane platform is going to implement fgetc by calling the
equivalent of read(2) more than once. fgetc has to be able to
return without filling its buffer to preserve errno when errors are
encountered anyway. So let's assume the simpler behavior (trust) but
add some tests to catch insane platforms that violate that when they
come (verify).
First check that fread can handle a 0-length read from an empty fifo.
Because open(O_RDONLY) blocks until the writing end is open, open the
writing end of the fifo in advance in a subshell.
Next try short inputs from a pipe that is not filled all the way.
Lastly (two tests) try very large inputs from a pipe that will not fit
in the relevant buffers. The first of these tests reads a little
more than 8192 bytes, which is BUFSIZ (the size of stdio's buffers)
on this Linux machine. The second reads a little over 64 KiB (the
pipe capacity on Linux) and is not run unless requested by setting
the GIT_REMOTE_SVN_TEST_BIG_FILES environment variable.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Do not expect an implicit newline after each input record.
Use a separate command to exercise buffer_skip_bytes.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Split the line_buffer test into small pieces and move it to its
own file as preparation for adding more tests.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Jonathan Nieder
Jeff King