Fix a problme identified upstream for readline-8.3.

chapter08/readline.xml

@@ -56,6 +56,16 @@ sed -i '/{OLDSUFF}/c:' support/shlib-install</userinput></screen>
 
 <screen><userinput>sed -i 's/-Wl,-rpath,[^ ]*//' support/shobj-conf</userinput></screen>
 
+    <para>
+      Fix a problem identified upstream specifically for this version of readline:
+    </para>
+
+<screen><userinput>sed -e '270a\
+     else\
+       chars_avail = 1;'      \
+    -e '288i\   result = -1;' \
+    -i.orig input.c</userinput></screen>
+
     <para>Prepare Readline for compilation:</para>
 
 <screen><userinput remap="configure">./configure --prefix=/usr    \