bug#11858: df -m undocumented, why no df -g

[Jim Meyering]

Bernhard Voelker wrote:
> Subject: [PATCH] df: Warn if soon-to-be-removed --megabyte option is used
>
> * src/df.c: MEGABYTES_OPTION: Add new enum and mark it to be removed
> in August 2013.
> * src/df.c (long_options): Use MEGABYTES_OPTION for --megabytes option.
> * src/df.c (main): Add case for MEGABYTES_OPTION and issue a deprecation
> warning if the long form is being used. Document the short -m option to
> exist only for BSD compatibility.

Thanks.  Applied with log tweaks (e.g., s/W/w/ in summary, removed
each "* src/df.c" after the first -- "*" introduces a new file).

>From 5e78bbd163dbc739e168fc2bff6273a2b6e5e5de Mon Sep 17 00:00:00 2001
From: Bernhard Voelker <address@hidden>
Date: Wed, 11 Jul 2012 17:27:20 +0200
Subject: [PATCH] df: warn if soon-to-be-removed --megabyte option is used

* src/df.c (MEGABYTES_OPTION): Add enum and mark it for removal
in August 2013.
(long_options): Use MEGABYTES_OPTION for --megabytes option.
(main): Add a case for it and issue a deprecation warning if
the long form is used.  Document the short -m option to
exist only for BSD compatibility.
---
 src/df.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/df.c b/src/df.c
index e99fedf..7e30d57 100644
--- a/src/df.c
+++ b/src/df.c
@@ -167,7 +167,8 @@ static size_t nrows;
 enum
 {
   NO_SYNC_OPTION = CHAR_MAX + 1,
-  SYNC_OPTION
+  SYNC_OPTION,
+  MEGABYTES_OPTION  /* FIXME: remove long opt in Aug 2013 */
 };

 static struct option const long_options[] =
@@ -178,7 +179,7 @@ static struct option const long_options[] =
   {"human-readable", no_argument, NULL, 'h'},
   {"si", no_argument, NULL, 'H'},
   {"local", no_argument, NULL, 'l'},
-  {"megabytes", no_argument, NULL, 'm'}, /* obsolescent */
+  {"megabytes", no_argument, NULL, MEGABYTES_OPTION}, /* obsolescent,  */
   {"portability", no_argument, NULL, 'P'},
   {"print-type", no_argument, NULL, 'T'},
   {"sync", no_argument, NULL, SYNC_OPTION},
@@ -951,7 +952,14 @@ main (int argc, char **argv)
         case 'l':
           show_local_fs = true;
           break;
-        case 'm': /* obsolescent */
+        case MEGABYTES_OPTION:
+          /* Distinguish between the long and the short option.
+             As we want to remove the long option soon,
+             give a warning when the long form is used.  */
+          error (0, 0, "%s%s", _("warning: "),
+            _("long option '--megabytes' is deprecated"
+              " and will soon be removed"));
+        case 'm': /* obsolescent, exists for BSD compatibility */
           human_output_opts = 0;
           output_block_size = 1024 * 1024;
           break;
--
1.7.11.1.165.g299666c