id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc	lang	patch	platform
1630	null arguments automatically coerce to empty strings	pmichaud		"While working on PCT and POST updates today, I ran into the following:

{{{
pmichaud@orange:~/parrot/trunk$ cat ../z.pir

.sub 'hello'
    null $P0
    'xyz'($P0)
.end

.sub 'xyz'
    .param string abc
    print ""'""
    print abc
    print ""'\n""
.end

pmichaud@orange:~/parrot/trunk$ ./parrot ../z.pir
''
pmichaud@orange:~/parrot/trunk$ 
}}}

The null PMC argument is automatically being coerced into an empty string, instead of throwing a ""Null PMC"" exception.  I spent a good hour chasing down a problem in PCT due to this little buglet.

The behavior apparently changed sometime between 1.4.0 and 2.0.0 (probably resulting from pcc changes):

{{{
pmichaud@orange:~/parrot/RELEASE_1_4_0$ cat ../z.pir

.sub 'hello'
    null $P0
    'xyz'($P0)
.end

.sub 'xyz'
    .param string abc
    print ""'""
    print abc
    print ""'\n""
.end

pmichaud@orange:~/parrot/RELEASE_1_4_0$ ./parrot ../z.pir
Null PMC access in get_string()
current instr.: 'xyz' pc 15 (../z.pir:7)
called from Sub 'hello' pc 10 (../z.pir:4)
pmichaud@orange:~/parrot/RELEASE_1_4_0$ 

----

pmichaud@orange:~/parrot/RELEASE_2_0_0$ cat ../z.pir

.sub 'hello'
    null $P0
    'xyz'($P0)
.end

.sub 'xyz'
    .param string abc
    print ""'""
    print abc
    print ""'\n""
.end

pmichaud@orange:~/parrot/RELEASE_2_0_0$ ./parrot ../z.pir
''
pmichaud@orange:~/parrot/RELEASE_2_0_0$ 
}}}


Pm"	bug	closed	normal		none	2.0.0	medium	fixed