It's the clear intention of the combination of 137a0d0ef56 (Flush progress message buffer in display()., 2007-11-19) and 85cb8906f0e (progress: no progress in background, 2015-04-13) to call fflush(stderr) when we have a stderr in the foreground, but we ended up always calling fflush(stderr) seemingly by omission. Let's not. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> --- progress.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/progress.c b/progress.c index 7fcc513717..1fade5808d 100644 --- a/progress.c +++ b/progress.c @@ -91,7 +91,8 @@ static void display(struct progress *progress, uint64_t n, const char *done) } if (show_update) { - if (is_foreground_fd(fileno(stderr)) || done) { + int stderr_is_foreground_fd = is_foreground_fd(fileno(stderr)); + if (stderr_is_foreground_fd || done) { const char *eol = done ? done : "\r"; size_t clear_len = counters_sb->len < last_count_len ? last_count_len - counters_sb->len + 1 : @@ -115,7 +116,8 @@ static void display(struct progress *progress, uint64_t n, const char *done) fprintf(stderr, "%s: %s%*s", progress->title, counters_sb->buf, (int) clear_len, eol); } - fflush(stderr); + if (stderr_is_foreground_fd) + fflush(stderr); } progress_update = 0; } -- 2.32.0.957.gd9e39d72fe6