[libvirt] [PATCHv3] parthelper: fix compilation without optimization

[Jim Meyering]

Eric Blake wrote:
> Daniel's patch works with gcc and CFLAGS containing -O (the
> autoconf default), but fails with non-gcc or with other
> CFLAGS (such as -g), since c-ctype.h declares c_isdigit as
> a macro only for certain compilation settings.
>
> * src/Makefile.am (libvirt_parthelper_LDFLAGS): Add gnulib
> library, for when c_isdigit is not a macro.
> * src/storage/parthelper.c (main): Avoid out-of-bounds
> dereference, noticed by Jim Meyering.
> ---
>
> change in v3: earlier code already guarantees that path is non-null
> if we got this far, but not whether it is non-empty
>
>  src/Makefile.am          |    2 +-
>  src/storage/parthelper.c |    2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/src/Makefile.am b/src/Makefile.am
> index 6bdf73c..2129960 100644
> --- a/src/Makefile.am
> +++ b/src/Makefile.am
> @@ -1035,13 +1035,13 @@ if WITH_STORAGE_DISK
>  if WITH_LIBVIRTD
>  libexec_PROGRAMS += libvirt_parthelper
>
>  libvirt_parthelper_SOURCES = $(STORAGE_HELPER_DISK_SOURCES)
>  libvirt_parthelper_LDFLAGS = $(WARN_LDFLAGS) $(COVERAGE_LDFLAGS)
>  libvirt_parthelper_LDADD = $(LIBPARTED_LIBS)
> -libvirt_parthelper_CFLAGS =  $(LIBPARTED_CFLAGS)
> +libvirt_parthelper_CFLAGS = $(LIBPARTED_CFLAGS) ../gnulib/lib/libgnu.la
>  endif
>  endif
>  EXTRA_DIST += $(STORAGE_HELPER_DISK_SOURCES)
>
>
>  if WITH_LXC
> diff --git a/src/storage/parthelper.c b/src/storage/parthelper.c
> index 28d88c9..ca74456 100644
> --- a/src/storage/parthelper.c
> +++ b/src/storage/parthelper.c
> @@ -66,13 +66,13 @@ int main(int argc, char **argv)
>      } else if (argc != 2) {
>          fprintf(stderr, "syntax: %s DEVICE [-g]\n", argv[0]);
>          return 1;
>      }
>
>      path = argv[1];
> -    partsep = c_isdigit(path[strlen(path)-1]) ? "p" : "";
> +    partsep = *path && c_isdigit(path[strlen(path)-1]) ? "p" : "";
>
>      if ((dev = ped_device_get(path)) == NULL) {
>          fprintf(stderr, "unable to access device %s\n", path);
>          return 2;
>      }

Looks good.
ACK