quoting in heredocs zsh vs. /bin/sh

[Greg Steuck <greg-openbsd-ports@y2004.nest.cx>]

Hello,

I am trying to make a port of ion2 and the thing started using GNU
configure (it worked so well without it, why add it now?).

Anyway, configure has the following fragment:

cat >>conftest.$ac_ext <<_ACEOF 
... stuff
        printf("(found \"%s\")... ", lua_version()); 
... more stuff
_ACEOF 

executing this fragment with /bin/sh results in:
        printf("(found "%s")... ", lua_version()); 

executing with /bin/zsh results in:
        printf("(found \"%s\")... ", lua_version()); 

Obviously the former does not compile and configure fails.

Is OpenBSD ksh doing the right thing here? Should the test be fixed
or the shell?

Thanks
Greg