End tag causes two parse errors

[stevecheckoway]

<math><annotation-xml></svg>x

The </svg> is parsed in foreign context because

1. The stack of open elements is not empty;
2. The adjusted current node (annotation-xml element) is not in the
   HTML namespace;
3. The adjusted current node is not a MathML text integration point;
4. The adjusted current node is not a MathML text integration point
   (separate condition from 3);
5. The adjusted current node is a MathML annotation-xml element but
   the token (</svg>) is not a start tag;
6. The token is not a start tag (also the annotation-xml isn't an HTML
   integration point because it lacks a particular attribute);
7. The token isn't a character token (also the annotation-xml isn't an
   HTML integration point).

Thus the "any other end tag" clause of 12.2.6.5 "The rules for parsing
tokens in foreign context" applies.

The current node's tag name (annotation-xml) is not the same as the
tag name of the token (svg) so this is a parse error.

Since there's no svg element in the stack of open elements, the loop
in step 3 through 6 of the "any other end tag" clause exits when the
body element is reached. and the token is processed according to the
current insertion mode, "in body."

The </svg> matches the "any other end tag" of "in body." Since the
MathML annotation-xml element is not an HTML element but is special
which is a second parse error.