When reading a yaml::SequenceTraits object, YAMLIO does not report an
error if the yaml item is not a sequence. Instead, YAMLIO reads an
empty sequence. For example:
---
seq:
foo: 1
bar: 2
...
If `seq` is a SequenceTraits object, then reading the above yaml will
yield `seq` as an empty sequence.
Fix this to report an error for the above mapping ("not a sequence")
Patch by William Fisher. Thanks!
llvm-svn: 230976
64d2cdf4ec