[PATCH 0/8] progress: assert "global_progress" + test fixes / cleanup

These patches were originally submitted as part of a much larger topic at [1]. The add a "global_progress" "struct progress *" which we assign/clear to as we start/stop progress bars.

This will become imporant for some new progress features I have planend, but right now is just used to assert that we don't start two progress bars at the same time. 7/8 fixes an existing bug where we did that.

To get there I fixed up the test helper to be able to test this, moved some code around, and fixes a couple of existing nits in 5/8 and 6/8..

See also [2] which is a re-submission of that larger topic, but the two can proceed independently.

1. https://lore.kernel.org/git/cover-00.25-00000000000-20210623T155626Z-avarab@gmail.com/
2. https://lore.kernel.org/git/cover-0.3-0000000000-20210722T121801Z-avarab@gmail.com/

Ævar Arnfjörð Bjarmason (8):
  progress.c tests: make start/stop verbs on stdin
  progress.c tests: test some invalid usage
  progress.c: move signal handler functions lower
  progress.c: call progress_interval() from progress_test_force_update()
  progress.c: stop eagerly fflush(stderr) when not a terminal
  progress.c: add temporary variable from progress struct
  pack-bitmap-write.c: add a missing stop_progress()
  progress.c: add & assert a "global_progress" variable

 pack-bitmap-write.c         |   1 +
 progress.c                  | 116 ++++++++++++++++++++----------------
 t/helper/test-progress.c    |  43 +++++++++----
 t/t0500-progress-display.sh | 103 +++++++++++++++++++++++++-------
 4 files changed, 178 insertions(+), 85 deletions(-)