11.1-RELEASE: new line containing garbage added to "top"

[Peter]

Glen Barber wrote:
> On Fri, Jul 28, 2017 at 07:04:51PM +0200, Peter wrote:
>> Glen Barber wrote:
>>> On Fri, Jul 28, 2017 at 03:24:50PM +0200, Peter wrote:
>>>> After upgrading to 11.1-RELEASE, a new line appears in the output of "top"
>>>> which contains rubbish:
>>>>
>>>>> last pid: 10789;  load averages:  5.75,  5.19,  3.89    up 0+00:34:46 03:23:51
>>>>> 1030 processes:9 running, 1004 sleeping, 17 waiting
>>>>> CPU 0: 16.0% user,  0.0% nice, 78.7% system,  4.9% interrupt,  0.4% idle
>>>>> CPU 1:  8.0% user,  0.0% nice, 82.5% system,  9.1% interrupt,  0.4% idle
>>>>> Mem: 218M Active, 34M Inact, 105M Laundry, 600M Wired, 18M Buf, 34M Free
>>>>> ARC: 324M Total, 54M MFU, 129M MRU, 2970K Anon, 13M Header, 125M Other
>>>>>      136¿176M Compress185 194M Uncompressed361.94:1 Ratio
>>>>> Swap: 2441M Total, 277M Used, 2164M Free, 11% Inuse
>>>>
>>>>>   PID USERNAME   PRI NICE   SIZE    RES STATE   C   TIME    WCPU COMMAND
>>>> ..
>>>>
>>>>
>>>> That looks funny. But I dont like it.
>>>>
>>>
>>> It appears to be fixed in 11-STABLE (r321419).
>>>
>>> Glen
>>>
>>
>> I don't think so. At least there is nothing in the commitlog. r318449 is the
>> last commit in 11-STABLE for the respective file; and thats before the
>> 11.1-RELEASE branch.
>>
>
> See r321419.


Yes, thats the issue with the empty line when ZFS is *not* in use, which 
I mentioned below (bug #220996). For that a fix is committed.


>> The error is in the screen-formatting in "top", and that error was already
>> present back in 1997 (and probably earlier), and it is also present in HEAD.
>>
>> What "top" does is basically this:
>>
>>> char *string = some_buffer_to_print;
>>> printf("%.5s", &string[-4]);
>>
>> A negative index on a string usually yields a nullified area. (Except if
>> otherwise *eg*) Thats why we usually don't see the matter - nullbytes are
>> invisible on screen.
>>
>> Fix is very simple:
>>
>> Index: contrib/top/display.c
>> ===================================================================
>> --- display.c   (revision 321434)
>> +++ display.c   (working copy)
>> @@ -1310,7 +1310,7 @@
>>         cursor_on_line = Yes;
>>         putchar(ch);
>>         *old = ch;
>> -       lastcol = 1;
>> +       lastcol++;
>>      }
>>      old++;
>>
>>
>> ---------------------------------------------------------
>> Then, since I was at it, I decided to beautify the proc display as well, as
>> I usually see >1000 procs:
>>
>>
>> --- display.c   (revision 321434)
>> +++ display.c   (working copy)
>> @@ -100,7 +100,7 @@
>>  int  y_loadave =       0;
>>  int  x_procstate =     0;
>>  int  y_procstate =     1;
>> -int  x_brkdn =         15;
>> +int  x_brkdn =         16;
>>  int  y_brkdn =         1;
>>  int  x_mem =           5;
>>  int  y_mem =           3;
>> @@ -373,9 +373,9 @@
>>      printf("%d processes:", total);
>>      ltotal = total;
>>
>> -    /* put out enough spaces to get to column 15 */
>> +    /* put out enough spaces to get to column 16 */
>>      i = digits(total);
>> -    while (i++ < 4)
>> +    while (i++ < 5)
>>      {
>>         putchar(' ');
>>      }
>>
>>
>> ----------------------------------------------------------------
>> Then, concerning the complaint about the empty line (bug #220996), I
>> couldn't really reproduce this. But it seems that specifically this issue
>> was already fixed in HEAD by this one here:
>> https://reviews.freebsd.org/D11693
>>
>> ----------------------------------------------------------------
>> Now, can anybody make the above snippets appear in HEAD and 11-STABLE?
>>
>
> I've CC'd allanjude, who has touched some of these in the past.

Thanks a lot!