split: honor $TMPDIR for temp files

* bootstrap.conf: Depend on tmpdir rather than tmpfile,
as the standard tmpfile() doesn't honor $TMPDIR.
* src/split.c (copy_to_tmpfile): Adjust to call temp_stream() rather
than tmpfile();
* NEWS: Mention the improvement.

NEWS

@@ -68,6 +68,8 @@ GNU coreutils NEWS                                    -*- outline -*-
   split now uses more tuned access patterns for its potentially large input.
   This was seen to improve throughput by 5% when reading from SSD.
 
+  split now supports a configurable $TMPDIR for handling any temporary files.
+
   tac now falls back to '/tmp' if a configured $TMPDIR is unavailable.
 
 

bootstrap.conf

@@ -274,7 +274,7 @@ gnulib_modules="
   time_rz
   timer-time
   timespec
-  tmpfile
+  tmpdir
   tzset
   uname
   unicodeio

src/local.mk

@@ -396,6 +396,7 @@ src_arch_SOURCES = src/uname.c src/uname-arch.c
 src_cut_SOURCES = src/cut.c src/set-fields.c
 src_numfmt_SOURCES = src/numfmt.c src/set-fields.c
 
+src_split_SOURCES = src/split.c src/temp-stream.c
 src_tac_SOURCES = src/tac.c src/temp-stream.c
 
 src_tail_SOURCES = src/tail.c src/iopoll.c

src/split.c

@@ -40,6 +40,7 @@
 #include "quote.h"
 #include "sig2str.h"
 #include "sys-limits.h"
+#include "temp-stream.h"
 #include "xbinary-io.h"
 #include "xdectoint.h"
 #include "xstrtol.h"
@@ -279,8 +280,8 @@ CHUNKS may be:\n\
 static off_t
 copy_to_tmpfile (int fd, char *buf, idx_t bufsize)
 {
-  FILE *tmp = tmpfile ();
-  if (!tmp)
+  FILE *tmp;
+  if (!temp_stream (&tmp, nullptr))
     return -1;
   off_t copied = 0;
   off_t r;