Patch #711902: Cause pydoc to show data descriptor __doc__ strings.
diff --git a/Doc/lib/libinspect.tex b/Doc/lib/libinspect.tex
index a1293f0..cc41f2f 100644
--- a/Doc/lib/libinspect.tex
+++ b/Doc/lib/libinspect.tex
@@ -161,6 +161,31 @@
Return true if the object is a user-defined or built-in function or method.
\end{funcdesc}
+\begin{funcdesc}{ismethoddescriptor}{object}
+ Return true if the object is a method descriptor, but not if ismethod() or
+ isclass() or isfunction() are true.
+
+ This is new as of Python 2.2, and, for example, is true of int.__add__.
+ An object passing this test has a __get__ attribute but not a __set__
+ attribute, but beyond that the set of attributes varies. __name__ is
+ usually sensible, and __doc__ often is.
+
+ Methods implemented via descriptors that also pass one of the other
+ tests return false from the ismethoddescriptor() test, simply because
+ the other tests promise more -- you can, e.g., count on having the
+ im_func attribute (etc) when an object passes ismethod().
+\end{funcdesc}
+
+\begin{funcdesc}{isdatadescriptor}{object}
+ Return true if the object is a data descriptor.
+
+ Data descriptors have both a __get__ and a __set__ attribute. Examples are
+ properties (defined in Python) and getsets and members (defined in C).
+ Typically, data descriptors will also have __name__ and __doc__ attributes
+ (properties, getsets, and members have both of these attributes), but this
+ is not guaranteed.
+\end{funcdesc}
+
\subsection{Retrieving source code
\label{inspect-source}}