* Fix parsing empty Struct Values from Json
This fixes a bug. When parsing a struct from JSON like
struct = json_format.Parse('{"k": {}}', Struct())
then the struct's "k" value would end up not initialized, and accessing
the value would raise an error.
In[1]: struct['k']
ValueError: Value not set
That seems to be because the Struct field of the Value was not set.
In[2]: struct
Out[2]:
fields {
key: "k"
value {
}
}
This commit makes sure that the Value's Struct field is initialized even
if the Struct has no values itself.
This commit also extends a test to cover this case.
* Additionally test for empty list
Leon Barrett
9e69594adf