Fix regression introduced with commit 74dcc10b

The code wasn't dead after all, but I can see no reason in delaying
the XPointer evaluation. This could lead to nodes included earlier
appearing in XPointer results.

result/XInclude/ns1.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<doc xmlns:xi="http://www.w3.org/2001/XInclude">
+    <ns:elem xmlns:ns="urn:foo" xml:id="a"/>
+    <elem xmlns:ns="urn:foo">
+        <ns:elem xml:id="a"/>
+    </elem>
+    
+            <ns:elem xmlns:ns="urn:bar"/>
+        
+</doc>

result/XInclude/ns1.xml.rdr

@@ -0,0 +1,23 @@
+0 1 doc 0 0
+1 14 #text 0 1 
+    
+1 1 ns:elem 1 0
+1 14 #text 0 1 
+    
+1 1 elem 0 0
+2 14 #text 0 1 
+        
+2 1 ns:elem 1 0
+2 14 #text 0 1 
+    
+1 15 elem 0 0
+1 14 #text 0 1 
+    
+1 14 #text 0 1 
+            
+1 1 ns:elem 1 0
+1 14 #text 0 1 
+        
+1 14 #text 0 1 
+
+0 15 doc 0 0

test/XInclude/docs/ns1.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+<doc xmlns:xi="http://www.w3.org/2001/XInclude">
+    <xi:include href="#a"/>
+    <elem xmlns:ns="urn:foo">
+        <ns:elem xml:id="a"/>
+    </elem>
+    <xi:include href="b.xml">
+        <xi:fallback xmlns:ns="urn:bar">
+            <ns:elem/>
+        </xi:fallback>
+    </xi:include>
+</doc>

xinclude.c

@@ -1464,7 +1464,7 @@ xmlXIncludeLoadDoc(xmlXIncludeCtxtPtr ctxt, const xmlChar *url, int nr) {
      */
     if ((URL[0] == 0) || (URL[0] == '#') ||
 	((ctxt->doc != NULL) && (xmlStrEqual(URL, ctxt->doc->URL)))) {
-	doc = NULL;
+	doc = ctxt->doc;
         goto loaded;
     }