split: fix cases where -n l/... creates extraneous files

* 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.

1 files changed, 16 insertions, 0 deletions

diff --git a/tests/misc/split-lchunk b/tests/misc/split-lchunk
index 0f1693b3c..762138b97 100755
--- a/tests/misc/split-lchunk
+++ b/tests/misc/split-lchunk
@@ -34,6 +34,12 @@ split -n l/10 /dev/null || fail=1
 test "$(stat -c %s x* | uniq -c | sed 's/^ *//; s/ /x/')" = "10x0" || fail=1
 rm x??
 
+# Ensure the correct number of files written
+# even if there is more data than the reported file size
+split -n l/2 /dev/zero
+test "$(stat -c %s x* | wc -l)" = '2' || fail=1
+rm x??
+
 # Ensure --elide-empty-files is honored
 split -e -n l/10 /dev/null || fail=1
 stat x?? 2>/dev/null && fail=1
@@ -66,9 +72,19 @@ for ELIDE_EMPTY in '' '-e'; do
     test "$DEBUGGING" && printf "\n---io-blk-size=$IO_BLKSIZE $ELIDE_EMPTY\n"
     for N in 6 8 12 15 22; do
       rm -f x*
+
+      if test -z "$ELIDE_EMPTY"; then
+        split ---io-blksize=$IO_BLKSIZE $ELIDE_EMPTY -n l/2/$N in > chunk.k
+        stat x* >/dev/null 2>/dev/null && fail=1
+      fi
+
       split ---io-blksize=$IO_BLKSIZE $ELIDE_EMPTY -n l/$N in
       echo $(stat -c "%02s" x*) >> out
 
+      if test -z "$ELIDE_EMPTY"; then
+        compare chunk.k xab || fail=1
+      fi
+
       if test "$DEBUGGING"; then
         # Output partition pattern
         size=$(printf "%s" "$lines" | wc -c)