[PATCH v9 0/9] progress: test fixes / cleanup

A re-roll of this series of various basic fixes to the progress API.

This addresses all the comments brought up on v8, thanks a lot to René and Johannes Altmanninger. It just took me about to a month to get around to re-rolling this.

There's various small fixes early in the series. I amended some commit messages, added a mising promised test etc.

But most significantly as René pointed out stop_progress() and stop_progress_msg() should really be unified. This series does that, which fixes a long-standing bug with the trace2 region not being ended if the stop_progress_msg() variant was called.

This is a reply to the v6, which is the thread this was originally in[1]. In v7[2] I didn't add In-Reply-T, and in v8[3] I ended up replying to the wrong thread! Sorry about that.

I then ejected the isatty() change. That was done for a final addition of a BUG() assertion that's now gone, but which I plan to submit after this series. I can re-visit that if and when I re-roll that.

1. https://lore.kernel.org/git/cover-v6-0.8-00000000000-20211102T122507Z-avarab@gmail.com
2. https://lore.kernel.org/git/cover-v7-0.7-00000000000-20211217T041945Z-avarab@gmail.com
3. https://lore.kernel.org/git/cover-v8-0.7-00000000000-20211228T150728Z-avarab@gmail.com

Ævar Arnfjörð Bjarmason (9):
  leak tests: fix a memory leak in "test-progress" helper
  progress.c test helper: add missing braces
  progress.c tests: make start/stop commands on stdin
  progress.c tests: test some invalid usage
  progress.h: format and be consistent with progress.c naming
  progress.c: use dereferenced "progress" variable, not "(*p_progress)"
  progress.c: refactor stop_progress{,_msg}() to use helpers
  progress API: unify stop_progress{,_msg}(), fix trace2 bug
  pack-bitmap-write.c: don't return without stop_progress()

 pack-bitmap-write.c         |   6 +-
 progress.c                  |  66 ++++++++++------------
 progress.h                  |   9 ++-
 t/helper/test-progress.c    |  50 ++++++++++++-----
 t/t0500-progress-display.sh | 109 +++++++++++++++++++++++++++++-------
 t/t5316-pack-delta-depth.sh |   6 +-
 6 files changed, 170 insertions(+), 76 deletions(-)

Range-diff against v8:
 1:  aa08dab654d =  1:  dc304df9468 leak tests: fix a memory leak in "test-progress" helper
 2:  3ecdab074b6 =  2:  6951c059aa9 progress.c test helper: add missing braces
 3:  271f6d7ec3b !  3:  4548144a0b4 progress.c tests: make start/stop commands on stdin
    @@ t/helper/test-progress.c
     +		if (skip_prefix(line.buf, "start ", (const char **) &end)) {
     +			uint64_t total = strtoull(end, &end, 10);
     +			const char *title;
    -+			const char *str;
     +
     +			/*
     +			 * We can't use "end + 1" as an argument to
    @@ t/helper/test-progress.c
     +			else
     +				die("invalid input: '%s'\n", line.buf);
     +
    -+			str = title ? title : default_title;
    -+			progress = start_progress(str, total);
    ++			progress = start_progress(title, total);
     +		} else if (skip_prefix(line.buf, "progress ", (const char **) &end)) {
      			uint64_t item_count = strtoull(end, &end, 10);
      			if (*end != '\0')
 4:  7c1b8b287c5 !  4:  965d4ba7b54 progress.c tests: test some invalid usage
    @@ Commit message
         progress.c tests: test some invalid usage
     
         Test what happens when we "stop" without a "start", omit the "stop"
    -    after a "start", or try to start two concurrent progress bars. This
    +    after a "start", or start two concurrent progress bars. This
         extends the trace2 tests added in 98a13647408 (trace2: log progress
         time and throughput, 2020-05-12).
     
    @@ t/t0500-progress-display.sh: test_expect_success 'progress generates traces' '
     +	stop
     +	EOF
     +
    -+	GIT_TRACE2_EVENT="$(pwd)/trace-startstop.event" test-tool progress \
    ++	GIT_TRACE2_EVENT="$PWD/trace-startstop.event" test-tool progress \
     +		<in 2>stderr &&
     +	test_region progress "Working hard" trace-startstop.event
     +'
    @@ t/t0500-progress-display.sh: test_expect_success 'progress generates traces' '
     +	start 0
     +	EOF
     +
    -+	GIT_TRACE2_EVENT="$(pwd)/trace-start.event" \
    ++	GIT_TRACE2_EVENT="$PWD/trace-start.event" \
     +	LSAN_OPTIONS=detect_leaks=0 \
     +	test-tool progress \
     +		<in 2>stderr &&
    @@ t/t0500-progress-display.sh: test_expect_success 'progress generates traces' '
     +	stop
     +	EOF
     +
    -+	GIT_TRACE2_EVENT="$(pwd)/trace-stop.event" test-tool progress \
    ++	GIT_TRACE2_EVENT="$PWD/trace-stop.event" test-tool progress \
     +		<in 2>stderr &&
     +	! grep region_enter.*progress trace-stop.event &&
     +	! grep region_leave.*progress trace-stop.event
     +'
    ++
    ++test_expect_success 'progress generates traces: start with active progress bar (no stops)' '
    ++	cat >in <<-\EOF &&
    ++	start 0 One
    ++	start 0 Two
    ++	EOF
    ++
    ++	GIT_TRACE2_EVENT="$PWD/trace-2start.event" \
    ++	LSAN_OPTIONS=detect_leaks=0 \
    ++	test-tool progress \
    ++		<in 2>stderr &&
    ++	grep region_enter.*progress.*One trace-2start.event &&
    ++	grep region_enter.*progress.*Two trace-2start.event &&
    ++	! grep region_leave trace-2start.event
    ++'
     +
      test_done
 -:  ----------- >  5:  4ab4eb3a20a progress.h: format and be consistent with progress.c naming
 5:  72a31bd7191 !  6:  ab24cb78d73 progress.c: add temporary variable from progress struct
    @@ Metadata
     Author: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
     
      ## Commit message ##
    -    progress.c: add temporary variable from progress struct
    +    progress.c: use dereferenced "progress" variable, not "(*p_progress)"
     
         Since 98a13647408 (trace2: log progress time and throughput,
         2020-05-12) stop_progress() dereferences a "struct progress **"
    -    parameter in several places. Extract a dereferenced variable (like in
    -    stop_progress_msg()) to reduce clutter and make it clearer who needs
    -    to write to this parameter.
    +    parameter in several places. Extract a dereferenced variable to reduce
    +    clutter and make it clearer who needs to write to this parameter.
     
         Now instead of using "*p_progress" several times in stop_progress() we
         check it once for NULL and then use a dereferenced "progress" variable
    -    thereafter. This continues the same pattern used in the above
    -    stop_progress() function, see ac900fddb7f (progress: don't dereference
    -    before checking for NULL, 2020-08-10).
    +    thereafter. This uses the same pattern as the adjacent
    +    stop_progress_msg() function, see ac900fddb7f (progress: don't
    +    dereference before checking for NULL, 2020-08-10).
     
         Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
     
    @@ progress.c: static void finish_if_sparse(struct progress *progress)
      void stop_progress(struct progress **p_progress)
      {
     +	struct progress *progress;
    ++
      	if (!p_progress)
      		BUG("don't provide NULL to stop_progress");
     +	progress = *p_progress;
 -:  ----------- >  7:  3406d71b499 progress.c: refactor stop_progress{,_msg}() to use helpers
 -:  ----------- >  8:  62a93bb98b0 progress API: unify stop_progress{,_msg}(), fix trace2 bug
 6:  0bd08e1b018 =  9:  0b2248a2d74 pack-bitmap-write.c: don't return without stop_progress()
 7:  060483fb5ce <  -:  ----------- *.c: use isatty(0|2), not isatty(STDIN_FILENO|STDERR_FILENO)