Add an example about how to use EXTRA_PATCHES with a directory.

Sponsored by:	Absolight

en_US.ISO8859-1/books/porters-handbook/slow-porting/chapter.xml

@@ -492,6 +492,34 @@ BAR_EXTRA_PATCHES_OFF=	${PATCHDIR}/extra-patch-bar.c \
 		${PATCHDIR}/extra-patch-bar.h</programlisting>
       </example>
 
+      <example xml:id="slow-patch-extra-ex-dirs">
+	<title>Using <varname>EXTRA_PATCHES</varname> With a
+	  Directory</title>
+
+	<para>Sometime, there are many patches that are needed for a
+	  feature, in this case, it is possible to point
+	  <varname>EXTRA_PATCHES</varname> to a directory, and it will
+	  automatically apply all files named
+	  <filename>patch-<replaceable>*</replaceable></filename> in
+	  it.</para>
+
+	<para>Create a subdirectory in
+	  <filename>${PATCHDIR}</filename>, and move the patches in
+	  it.  For example:</para>
+
+	<screen>&prompt.user; <userinput>ls -l <replaceable>files/foo-patches</replaceable></userinput>
+-rw-r--r--  1 root  wheel    350 Jan 16 01:27 patch-Makefile.in
+-rw-r--r--  1 root  wheel   3084 Jan 18 15:37 patch-configure</screen>
+
+	<para>Then add this to the <filename>Makefile</filename>:</para>
+
+	<programlisting>OPTIONS_DEFINE=	FOO
+FOO_EXTRA_PATCHES=	${PATCHDIR}/foo-patches</programlisting>
+
+	<para>The framework will then use all the files named
+	  <filename>patch-<replaceable>*</replaceable></filename> in
+	  that directory.</para>
+      </example>
     </sect2>
   </sect1>