Hi guys,
yesturday and today, I fight against a vicious bug for hours. Thanks to
Pierre-Arnaud and Alex, I found the reason for the failures I was
experienced.
What happened is that the Key used to extract an entry from the master
table was compared with the stored Keys using a compare() method which
uses long, doing some simple if ( key1 > key2 ) then ... test.
This is obviously wrong if we are working with unsigned longs, because
Java does not treat longs as unsigned, so -1 is always > to any positive
value (because the upper bit is 1 for negative values), but java >
operator does not take this bit into account.
After a convo with David Jencks, we agreed that we need a four steps
comparison :
if ( x >= 0 and y >= 0) then return x > Y
if ( x < 0 and y >= 0) then return x
if ( x >= 0 and y < 0) then return y
if ( x < 0 and y < 0) then return -x < -y
I will implement such a method asap.
PS : trunk is simply broken if the DBFILES file is removed and
regenerated, as the plugin will inject data at the wrong place, due to
this bug, which has been introduced in october last year.
PS2 : there is a hack which seems to work :
if ( x - y ) > 0 the return x else return y
I don't have the fuel to check what will happen when (x - y) will
overflow though, but I will do tomorrow (unless somebody can check for me ;)
--
--
cordialement, regards,
Emmanuel Lécharny
www.iktek.com
directory.apache.org
