expr overflow or underflow breaks pkgsrc builds

[Chuck Zmudzinski <frchuckz%gmail.com@localhost>]

I see a strange behavior on current that breaks ability to build some 
packages from pkgsrc.

One package that does not work on NetBSD current is pkgtools/cwrappers

I am using a very recent checkout of pkgsrc-current and netbsd-current, 
both updated yesterday.

If you run 'make' in the pkgsrc/pkgtools/cwrappers directory, you will 
get this error:

expr: integer overflow or underflow occurred for operation '0 + 1'
*** Error code 2

Stop.
make[1]: stopped in /home/chuckz/pkgsrc-current/pkgtools/cwrappers
*** Error code 1

Stop.
make: stopped in 
/home/chuckz/netbsd/chuckz/obj.amd64/pkgsrc-current-current/pkgtools/cwrappers

Also, if you just run 'expr 0 + 1' from a shell you will see the same 
error message about integer overflow or underflow.

If you run the same command on NetBSD 7.1, you will get the expected 
expression and no error: 1

So to workaround I temporarily replaced /bin/expr with /bin/expr from 
NetBSD 7.1.

Then I can build packages that need to execute 'expr 0 + 1' during the 
build (I think this occurs in configure scripts for some important 
packages like cwrappers). I also tested the /bin/expr executable 
extracted from a recent daily snapshot build from yesterday and it gives 
the same error when evaluating 0 + 1.

Any ideas if this is expected behavior of /bin/expr?

Thanks,

Chuck Zmudzinski