Re: [Qemu-devel] [PATCH 2/2] qom: Fix ambiguous path detection when ambiguous=NULL

[Igor Mammedov <imammedo@redhat.com>]

On Fri,  7 Jul 2017 18:30:52 -0300
Eduardo Habkost <ehabkost@redhat.com> wrote:

> object_resolve_path*() ambiguous path detection breaks when
> ambiguous==NULL and the object tree have 3 objects of the same type and
> only 2 of them are under the same parent.  e.g.:
> 
>  /container/obj1 (TYPE_FOO)
>  /container/obj2 (TYPE_FOO)
>  /obj2 (TYPE_FOO)
> 
> With the above tree, object_resolve_path_type("", TYPE_FOO, NULL) will
> incorrectly return /obj2, because the search inside "/container" will
> return NULL, and the match at "/obj2" won't be detected as ambiguous.
> 
> Fix that by always calling object_resolve_partial_path() with a non-NULL
> ambiguous parameter.
> 
> Test case included.
> 
> Reported-by: Igor Mammedov <imammedo@redhat.com>
> Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  qom/object.c               | 17 ++++++++---------
>  tests/check-qom-proplist.c |  3 +++
>  2 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/qom/object.c b/qom/object.c
> index 5f6fdfa..0cdddcb 100644
> --- a/qom/object.c
> +++ b/qom/object.c
> @@ -1712,15 +1712,13 @@ static Object *object_resolve_partial_path(Object *parent,
>                                              typename, ambiguous);
>          if (found) {
>              if (obj) {
> -                if (ambiguous) {
> -                    *ambiguous = true;
> -                }
> +                *ambiguous = true;
>                  return NULL;
>              }
>              obj = found;
>          }
>  
> -        if (ambiguous && *ambiguous) {
> +        if (*ambiguous) {
>              return NULL;
>          }
>      }
> @@ -1729,7 +1727,7 @@ static Object *object_resolve_partial_path(Object *parent,
>  }
>  
>  Object *object_resolve_path_type(const char *path, const char *typename,
> -                                 bool *ambiguous)
> +                                 bool *ambiguousp)
>  {
>      Object *obj;
>      gchar **parts;
> @@ -1738,11 +1736,12 @@ Object *object_resolve_path_type(const char *path, const char *typename,
>      assert(parts);
>  
>      if (parts[0] == NULL || strcmp(parts[0], "") != 0) {
> -        if (ambiguous) {
> -            *ambiguous = false;
> -        }
> +        bool ambiguous = false;
>          obj = object_resolve_partial_path(object_get_root(), parts,
> -                                          typename, ambiguous);
> +                                          typename, &ambiguous);
> +        if (ambiguousp) {
> +            *ambiguousp = ambiguous;
> +        }
>      } else {
>          obj = object_resolve_abs_path(object_get_root(), parts, typename, 1);
>      }
> diff --git a/tests/check-qom-proplist.c b/tests/check-qom-proplist.c
> index abafbd7..381532c 100644
> --- a/tests/check-qom-proplist.c
> +++ b/tests/check-qom-proplist.c
> @@ -593,14 +593,17 @@ static void test_qom_partial_path(void)
>      ambiguous = false;
>      g_assert(!object_resolve_path_type("", TYPE_DUMMY, &ambiguous));
>      g_assert(ambiguous);
> +    g_assert(!object_resolve_path_type("", TYPE_DUMMY, NULL));
>  
>      ambiguous = false;
>      g_assert(!object_resolve_path("obj2", &ambiguous));
>      g_assert(ambiguous);
> +    g_assert(!object_resolve_path("obj2", NULL));
>  
>      ambiguous = false;
>      g_assert(object_resolve_path("obj1", &ambiguous) == obj1);
>      g_assert(!ambiguous);
> +    g_assert(object_resolve_path("obj1", NULL) == obj1);
>  
>      object_unparent(obj1);
>      object_unparent(obj2a);