Re: [RESEND PATCH 02/12] golang/xenlight: fix StringList toC conversion

[George Dunlap <George.Dunlap@citrix.com>]

> On May 24, 2021, at 9:36 PM, Nick Rosbrook <rosbrookn@gmail.com> wrote:
> 
> The current implementation of StringList.toC does not correctly account
> for how libxl_string_list is expected to be laid out in C, which is clear
> when one looks at libxl_string_list_length in libxl.c. In particular,
> StringList.toC does not account for the extra memory that should be
> allocated for the "sentinel" entry. And, when using the "slice trick" to
> create a slice that can address C memory, the unsafe.Pointer conversion
> should be on a C.libxl_string_list, not *C.libxl_string_list.
> 
> Fix these problems by (1) allocating an extra slot in the slice used to
> address the C memory, and explicity set the last entry to nil so the C
> memory will be zeroed out, and (2) dereferencing csl in the
> unsafe.Pointer conversion.
> 
> Signed-off-by: Nick Rosbrook <rosbrookn@ainfosec.com>

Reviewed-by: George Dunlap <george.dunlap@citrix.com>

Even as I was making these I thought it might be good to try to get some unit tests of this conversion.