Please remove the extra newline before each return statement. It's inconsistent with the code styles used elsewhere in nscd (and in FreeBSD generally).

It'd be a bit more efficient to use realloc() in these loops.

This assignment to errno should happen right before returning from this function. It may get clobbered by free(), for example.

There should be a newline after variable declarations, and here there's an extra newline before the declaration.

A suggestion which would simplify this patch a bit: don't use errno to pass error numbers between these internal subroutines. Instead, add an extra parameter of type int * to getpw(), and modify getpw() to use it to return an error number instead of (ab)using errno.