On 20/06/2021 15:54, Nikolay Nechaev wrote:
* src/tail.c: remove excessive size checks before calls to `xwrite_stdout``xwrite_stdout` itself checks if what is to be printed out has positive size, and only proceeds then. There is no need to check if buffers are of positive size before printing them out with `xwrite_stdout` Signed-off-by: Nikolay Nechaev <nikolay_nech...@mail.ru> --- src/tail.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/src/tail.c b/src/tail.c index ff567560d..44a6e3e68 100644 --- a/src/tail.c +++ b/src/tail.c @@ -579,8 +579,7 @@ file_lines (char const *pretty_filename, int fd, uintmax_t n_lines, { /* If this newline isn't the last character in the buffer, output the part that is after it. */ - if (n != bytes_read - 1) - xwrite_stdout (nl + 1, bytes_read - (n + 1)); + xwrite_stdout (nl + 1, bytes_read - (n + 1)); *read_pos += dump_remainder (false, pretty_filename, fd, end_pos - (pos + bytes_read)); return true; @@ -881,8 +880,8 @@ start_bytes (char const *pretty_filename, int fd, uintmax_t n_bytes, else { size_t n_remaining = bytes_read - n_bytes; - if (n_remaining) - xwrite_stdout (&buffer[n_bytes], n_remaining); + // Print extra characters if there are any + xwrite_stdout (&buffer[n_bytes], n_remaining); break; } } @@ -923,8 +922,8 @@ start_lines (char const *pretty_filename, int fd, uintmax_t n_lines, ++p; if (--n_lines == 0) { - if (p < buffer_end) - xwrite_stdout (p, buffer_end - p); + // Print extra characters if there are any + xwrite_stdout (p, buffer_end - p); return 0; } }
This guard has been internal to the function since 1994: https://github.com/coreutils/coreutils/commit/32340b45e So all guards that check != 0 are redundant. However those that check >= 0 are not. The last one (in start_lines()) is such a case. I.e. p can be == buffer_end, so ++p == buffer_end +1, so buffer_end - p == -1. I will apply the first two chunks if you agree. thanks, Pádraig
