Based on The Open Group Base Specifications Issue 6 IEEE Std 1003.1, our

current implementation of df(1) is does not properly format the output under
certain conditions. Right now -kP and -Pk are not the same thing. Further,
when we set the BLOCKSIZE environment variable, we use "1k" instead of "1024",
making the header display incorrectly.

To quote the specification:

"When both the -k and -P options are specified, the following header line
 shall be written (in the POSIX locale):

"Filesystem 1024-blocks Used Available Capacity Mounted on\n"

- If -P has been specified, check to make sure that -k has not already been
  specified, if so, simply break instead of clobbering the previous blocksize
- Use 1024 instead of 1k to make the header POSIX compliant

Reported by:	Andriy Gapon
Discussed with:	bde, ru
MFC after:	1 week

1 files changed, 11 insertions, 2 deletions

diff --git a/bin/df/df.c b/bin/df/df.c
index 850c02f6826d..e33b3e4430bd 100644
--- a/bin/df/df.c
+++ b/bin/df/df.c
@@ -93,7 +93,7 @@ imax(int a, int b)
 	return (a > b ? a : b);
 }
 
-static int	aflag = 0, cflag, hflag, iflag, nflag;
+static int	aflag = 0, cflag, hflag, iflag, kflag, nflag;
 static struct	ufs_args mdev;
 
 int
@@ -123,6 +123,14 @@ main(int argc, char *argv[])
 		case 'b':
 				/* FALLTHROUGH */
 		case 'P':
+			/*
+			 * POSIX specifically discusses the the behavior of
+			 * both -k and -P. It states that the blocksize should
+			 * be set to 1024. Thus, if this occurs, simply break
+			 * rather than clobbering the old blocksize.
+			 */
+			if (kflag)
+				break;
 			putenv("BLOCKSIZE=512");
 			hflag = 0;
 			break;
@@ -143,7 +151,8 @@ main(int argc, char *argv[])
 			iflag = 1;
 			break;
 		case 'k':
-			putenv("BLOCKSIZE=1k");
+			kflag++;
+			putenv("BLOCKSIZE=1024");
 			hflag = 0;
 			break;
 		case 'l':