* src/split.c (lines_chunk_split): Ensure that data is only
written to stdout when k specified. Also ensure that
extra files are not created when there is more data available
than reported in the file size.
* tests/misc/split-lchunk: Verify that split -n l/k/n doesn't
generate any files, and that -n l/n always generates n files.
* NEWS: Mention the fix.
When -n l/N is used and long lines are present that both
span partitions and multiple buffers, one would get
inconsistent chunk sizes.
* src/split.c (main): Add a new undocumented ---io-blksize option
to support full testing with varied buffer sizes.
(cwrite): Refactor most handling of --elide-empty to here.
(bytes_split): Remove handling of --elide-empty.
(lines_chunk_split): Likewise. The specific issue here
was the first handling of elide_empty_files interfered
with the replenishing of the input buffer.
* test/misc/split-lchunk: Add -e and the new ---io-blksize
combinations to the test.
* src/split.c (usage, long_options, main): New options --number,
--unbuffered, --elide-empty-files.
(set_suffix_length): New function to auto increase suffix length
to handle a specified number of files.
(create): New function. Refactored from cwrite() and ofile_open().
(bytes_split): Add max_files argument to support byte chunking.
(lines_chunk_split): New function. Split file into chunks of lines.
(bytes_chunk_extract): New function. Extract a chunk of file.
(of_info): New struct. Used by functions lines_rr and ofile_open
to keep track of file descriptors associated with output files.
(ofile_open): New function. Shuffle file descriptors when there
are more output files than available file descriptors.
(lines_rr): New function to distribute lines round-robin to files.
(chunk_parse): New function. Parses K/N syntax.
* tests/misc/split-bchunk: New test for byte chunking.
* tests/misc/split-lchunk: New test for line delimited chunking.
* tests/misc/split-rchunk: New test for round-robin chunking.
* tests/Makefile.am: Reference new tests.
* tests/misc/split-fail: Add failure scenarios for new options.
* tests/misc/split-l: Fix a typo. s/ln/split/.
* doc/coreutils.texi (split invocation): Document --number.
* NEWS: Mention the new feature.
* .mailmap: Map new email address for shortlog.
Signed-off-by: Pádraig Brady <P@draigBrady.com>