du: extra compat: with -k and -m, round sizes up

function                                             old     new   delta
print                                                 36      65     +29

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/coreutils/du.c b/coreutils/du.c
index 9c6ff88..1889c16 100644
--- a/coreutils/du.c
+++ b/coreutils/du.c
@@ -75,7 +75,7 @@
 
 struct globals {
 #if ENABLE_FEATURE_HUMAN_READABLE
-	unsigned long disp_hr;
+	unsigned long disp_unit;
 #else
 	unsigned disp_k;
 #endif
@@ -89,18 +89,27 @@
 #define INIT_G() do { } while (0)
 
 
-/* FIXME? coreutils' du rounds sizes up:
- * for example,  1025k file is shown as "2" by du -m.
- * We round to nearest.
- */
 static void print(unsigned long long size, const char *filename)
 {
 	/* TODO - May not want to defer error checking here. */
 #if ENABLE_FEATURE_HUMAN_READABLE
+# if ENABLE_DESKTOP
+	/* ~30 bytes of code for extra comtat:
+	 * coreutils' du rounds sizes up:
+	 * for example,  1025k file is shown as "2" by du -m.
+	 * We round to nearest if human-readable [too hard to fix],
+	 * else (fixed scale such as -m), we round up. To that end,
+	 * add yet another half of the unit before displaying:
+	 */
+	if (G.disp_unit)
+		size += (G.disp_unit-1) / (unsigned)(512 * 2);
+# endif
 	printf("%s\t%s\n",
-			/* size x 512 / G.disp_hr, show one fractional,
-			 * use suffixes if G.disp_hr == 0 */
-			make_human_readable_str(size, 512, G.disp_hr),
+			/* size x 512 / G.disp_unit.
+			 * If G.disp_unit == 0, show one fractional
+			 * and use suffixes
+			 */
+			make_human_readable_str(size, 512, G.disp_unit),
 			filename);
 #else
 	if (G.disp_k) {
@@ -199,10 +208,10 @@
 	INIT_G();
 
 #if ENABLE_FEATURE_HUMAN_READABLE
-	IF_FEATURE_DU_DEFAULT_BLOCKSIZE_1K(G.disp_hr = 1024;)
-	IF_NOT_FEATURE_DU_DEFAULT_BLOCKSIZE_1K(G.disp_hr = 512;)
+	IF_FEATURE_DU_DEFAULT_BLOCKSIZE_1K(G.disp_unit = 1024;)
+	IF_NOT_FEATURE_DU_DEFAULT_BLOCKSIZE_1K(G.disp_unit = 512;)
 	if (getenv("POSIXLY_CORRECT"))  /* TODO - a new libbb function? */
-		G.disp_hr = 512;
+		G.disp_unit = 512;
 #else
 	IF_FEATURE_DU_DEFAULT_BLOCKSIZE_1K(G.disp_k = 1;)
 	/* IF_NOT_FEATURE_DU_DEFAULT_BLOCKSIZE_1K(G.disp_k = 0;) - G is pre-zeroed */
@@ -220,13 +229,13 @@
 	opt = getopt32(argv, "aHkLsx" "d:" "lc" "hm", &G.max_print_depth);
 	argv += optind;
 	if (opt & OPT_h_for_humans) {
-		G.disp_hr = 0;
+		G.disp_unit = 0;
 	}
 	if (opt & OPT_m_mbytes) {
-		G.disp_hr = 1024*1024;
+		G.disp_unit = 1024*1024;
 	}
 	if (opt & OPT_k_kbytes) {
-		G.disp_hr = 1024;
+		G.disp_unit = 1024;
 	}
 #else
 	opt_complementary = "H-L:L-H:s-d:d-s:d+";
diff --git a/libbb/human_readable.c b/libbb/human_readable.c
index 5c7fc07..b4e0ef1 100644
--- a/libbb/human_readable.c
+++ b/libbb/human_readable.c
@@ -14,16 +14,11 @@
  *      representations (say, powers of 1024) and manipulating coefficients.
  *      The base ten "bytes" output could be handled similarly.
  *
- *   2) This routine always outputs a decimal point and a tenths digit when
- *      display_unit != 0.  Hence, it isn't uncommon for the returned string
+ *   2) This routine outputs a decimal point and a tenths digit when
+ *      display_unit == 0.  Hence, it isn't uncommon for the returned string
  *      to have a length of 5 or 6.
  *
- *      It might be nice to add a flag to indicate no decimal digits in
- *      that case.  This could be either an additional parameter, or a
- *      special value of display_unit.  Such a flag would also be nice for du.
- *
- *      Some code to omit the decimal point and tenths digit is sketched out
- *      and "#if 0"'d below.
+ *      If block_size is also 0, no decimal digits are printed.
  *
  * Licensed under GPLv2, see file LICENSE in this source tree.
  */