Pattern rule defined multiple times

[Rafael Laboissiere]

I apologize if the issue I discuss below has already been discussed here.  I
do not have much time to browse the mailing list archives.

I noticed a difference in behavior between v3.80 and v3.81 of make regarding
multiple defined pattern rules.  Consider the following Makefile:

####################################################################
all:
        @touch foo.x
        @$(MAKE) foo.y
                
%.y : %.x ; @echo first
                
%.y : %.x
        @echo second            
####################################################################

The behavior I would expect is the one of v3.80, in which the second rule
override the first:

    $ make --version
    GNU Make 3.80
    Copyright (C) 2002  Free Software Foundation, Inc.
    This is free software; see the source for copying conditions.
    There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
    PARTICULAR PURPOSE.
    $ make -s
    second

However, v3.81 behaves differently:

    $ make --version
    GNU Make 3.81beta4
    Copyright (C) 2003  Free Software Foundation, Inc.
    This is free software; see the source for copying conditions.
    There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
    PARTICULAR PURPOSE.

    This program built for i486-pc-linux-gnu
    $ make -s
    first

Is this an intended feature or a bug?  If the former, could you please
explain to me the rationale of having syntactically equivalent forms with
different semantics?

-- 
Rafael