diff: regression in 1.2?

[Claus Assmann]

There seems to be a regression in diff as compiled in DragonFly 1.2.
Example: have a file f1 and compare it to stdin:

diff f1 - <<EOF
something
EOF

works in 1.0A.  In 1.2 I get this error:
diff: missing operand after '-'

even though both diff versions are the same (GNU diffutils) 2.8.1

Maybe getopt() has been changed?