char() datatype looses strings of all spaces

I stumbled across this behavior today and it seems strange if not a bug:

-- this seems wrong
vsconf=# create table foo (f1 char(1));
CREATE TABLE
vsconf=# insert into foo values(' ');
INSERT 9002011 1
vsconf=# select ascii(f1) from foo;
ascii
-------
0
(1 row)

-- this is what I'd expect
vsconf=# create table foo2 (f1 varchar(1));
CREATE TABLE
vsconf=# insert into foo2 values(' ');
INSERT 9002015 1
vsconf=# select ascii(f1) from foo2;
ascii
-------
32
(1 row)

-- this seems wrong
vsconf=# create table foo4 (f1 char(5));
CREATE TABLE
vsconf=# insert into foo4 values(' ');
INSERT 9002022 1
vsconf=# select ascii(f1) from foo4;
ascii
-------
0
(1 row)

I looked for a few minutes at bpcharin(), but could not see exactly why
this is happening. Am I missing something wrt the char() data type, or
is this a bug?

Joe