Be explicit about the reference count of the original value of the
first parameter to PyString_Concat().
diff --git a/Doc/api/api.tex b/Doc/api/api.tex
index 58c2f45..02e31c9 100644
--- a/Doc/api/api.tex
+++ b/Doc/api/api.tex
@@ -1737,8 +1737,12 @@
\begin{cfuncdesc}{void}{PyString_Concat}{PyObject **string,
PyObject *newpart}
-Creates a new string object in \var{*string} containing the contents
-of \var{newpart} appended to \var{string}.
+Creates a new string object in \var{*string} containing the
+contents of \var{newpart} appended to \var{string}. The old value of
+\var{string} have its reference count decremented. If the new string
+cannot be created, the old reference to \var{string} will still be
+discarded and the value of \var{*string} will be set to
+\NULL{}; the appropriate exception will be set.
\end{cfuncdesc}
\begin{cfuncdesc}{void}{PyString_ConcatAndDel}{PyObject **string,