new, stricter interface rule:
in x.(T) x cannot be a nil (uninitialized) interface variable.
remove TODO per discussion.
DELTA=3 (1 added, 1 deleted, 1 changed)
OCL=29123
CL=29134
diff --git a/doc/go_spec.html b/doc/go_spec.html
index 7e66b65..4809d07 100644
--- a/doc/go_spec.html
+++ b/doc/go_spec.html
@@ -2210,7 +2210,8 @@
</pre>
<p>
-asserts that the value stored in <code>x</code> is of type <code>T</code>.
+asserts that <code>x</code> is not the zero interface value
+and that the value stored in <code>x</code> is of type <code>T</code>.
The notation <code>x.(T)</code> is called a <i>type assertion</i>.
The type of <code>x</code> must be an interface type.
</p>
@@ -2220,7 +2221,6 @@
(§Type identity and compatibility).
If <code>T</code> is an interface type, <code>x.(T)</code> asserts that the dynamic type
of <code>T</code> implements the interface <code>T</code> (§Interface types).
-<font color=red>TODO: gri wants an error if x is already of type T.</font>
</p>
<p>
If the type assertion holds, the value of the expression is the value
