False positive: knownConditionTrueFalse

[Pierre DEL PERUGIA]

Hi,

the following code:

void f ( unsigned u )
{
        if ( u > 0 )
        {
                u--;
                //
                if ( u == 0 )
                        g();
        }
}

produces (or I really don't see how) a false positive:

g.cpp:7:10: style: Condition 'u==0' is always false [knownConditionTrueFalse]
if ( u == 0 )
^
g.cpp:3:9: note: Assuming that condition 'u>0' is not redundant
if ( u > 0 )
^
g.cpp:5:3: note: u is decremented', new value is 4294967295
u--;
^
g.cpp:7:10: note: Condition 'u==0' is always false
if ( u == 0 )

Tested with 2.15 dev (e2fa3cb10).

Thanks

[CHR]

Thanks for reporting, ticket is here: https://trac.cppcheck.net/ticket/12681