SYS21 - Negative values sneaking into PCP01...!!! from 12/MKS - ItemBooking - MK200

This is a public service announcement.  FYI...

PCP01 is not really supposed to be populated with negative values...  There is a
reversal indicator flag to handle reversals...!!!
This is a really obscure problem and it only happens when we have a new person
booking production...  12/MKS...

If you enter a negative value into the "Quantity Good" field and press enter you
get an error...  "Value must not be less than 0.000. " - The field in question
redisplays the negative value entered but without the negative sign...  If the
user then presses F1 to display the help text that explains the error, and then
proceeds with the entry, the field containing the negative value with the
invisible negative sign then gets processed into the file PCP01 and subsequent
down-stream processing fails when attempting to process the negative value that
has sneaked into the file...  The resulting partial/incomplete bookings make a
real mess that is difficult and time consuming to repair...

The system fails to retest the field(s) containing the invisible negative sign
because the field has not been modified since the screen was repainted last
(when you returned from the help text screen)...  The solution includes changing
the edit code to an 'L' and conditioning the field(s) with the Modified Data
Tag...

We have modified the display file MK200FT with the DSPATR(MDT) and conditioned
this attribute with the same indicators as the value field(s)...  This solves
the problem of forcing the system to retest the fields when returning from the
F1=Help Text screen...  Changing the edit code for those value field(s) to an
'L' reveals the sign to the user and the people who support the users so that
if/when they do receive this error in the future the appropriate corrective
action will be easily determined.

We added the DSPATR(MDT) to 10 fields.  Depending on how you configure JBA,
there are 8 fields which may possibly be displayed on the GOOD line plus the
SCRAP and HELD quantities.

The RPG program was not modified to resolve this issue...  Only the DSPF.

This problem was discovered at V3.5.1 and was also found at V3.5.2B SP4.

Thank you.