Index: src/dw_gtk_viewport.c
===================================================================
RCS file: /sfhome/cvs/dillo/dillo/src/dw_gtk_viewport.c,v
retrieving revision 1.44
diff -p -u -r1.44 dw_gtk_viewport.c
--- src/dw_gtk_viewport.c	17 Oct 2004 13:39:51 -0000	1.44
+++ src/dw_gtk_viewport.c	19 Oct 2004 18:49:19 -0000
@@ -803,35 +803,40 @@ DwWidget* Dw_gtk_viewport_widget_at_poin
 /*
  * Add an anchor, and assign a position for it. For all widgets
  * directly or indirectly assigned to a viewports, anchors must be
- * unique, this is tested.
+ * unique, this is tested. "name" is copied, so no strdup is
+ * neccessary for the caller.
  *
- * The viewport gets the responsibility to free "name", so the caller
- * does not have to pass a copy, neither, the caller must free it.
+ * Return the copy on success, or NULL, when this anchor had already
+ * been added to the widget tree.
+ *
+ * The viewport gets the responsibility to free "name".
  */
-void p_Dw_gtk_viewport_add_anchor (DwWidget *widget,
-                                   gchar *name,
-                                   gint32 y)
+gchar* p_Dw_gtk_viewport_add_anchor (DwWidget *widget,
+                                     const gchar *name,
+                                     gint32 y)
 {
    GtkDwViewport *viewport;
    GtkDwViewportAnchor *anchor;
-   gboolean exists;
 
    _MSG("new anchor %p/'%s' -> %d\n", widget, name, y);
 
-   g_return_if_fail (widget->viewport != NULL);
+   g_return_val_if_fail (widget->viewport != NULL, NULL);
    viewport = GTK_DW_VIEWPORT (widget->viewport);
 
-   exists = 
-      g_hash_table_lookup_extended (viewport->anchors_table, name, NULL, NULL);
-   g_return_if_fail(!exists);
-
-   anchor = g_new (GtkDwViewportAnchor, 1);
-   anchor->name = name;
-   anchor->widget = widget;
-   anchor->y = y;
-
-   g_hash_table_insert (viewport->anchors_table, name, anchor);
-   Dw_gtk_viewport_update_anchor (viewport);
+   if(g_hash_table_lookup_extended (viewport->anchors_table, name, NULL, NULL))
+      /* Anchor does already exist. */
+      return NULL;
+   else {
+      anchor = g_new (GtkDwViewportAnchor, 1);
+      anchor->name = g_strdup (name);
+      anchor->widget = widget;
+      anchor->y = y;
+      
+      g_hash_table_insert (viewport->anchors_table, anchor->name, anchor);
+      Dw_gtk_viewport_update_anchor (viewport);
+      
+      return anchor->name;
+   }
 }
 
 
@@ -852,7 +857,7 @@ void p_Dw_gtk_viewport_change_anchor (Dw
    g_return_if_fail (widget->viewport != NULL);
    viewport = GTK_DW_VIEWPORT (widget->viewport);
 
-   exists = 
+   exists =
       g_hash_table_lookup_extended (viewport->anchors_table, name, NULL,
                                     &tmp_anchor);
    g_return_if_fail(exists);
Index: src/dw_gtk_viewport.h
===================================================================
RCS file: /sfhome/cvs/dillo/dillo/src/dw_gtk_viewport.h,v
retrieving revision 1.21
diff -p -u -r1.21 dw_gtk_viewport.h
--- src/dw_gtk_viewport.h	17 Oct 2004 13:39:51 -0000	1.21
+++ src/dw_gtk_viewport.h	19 Oct 2004 18:49:20 -0000
@@ -90,8 +90,8 @@ DwWidget*      a_Dw_gtk_viewport_widget_
                                                            gint32 vx,
                                                            gint32 vy);
 
-void           p_Dw_gtk_viewport_add_anchor      (DwWidget *widget,
-                                                  gchar *name,
+gchar*         p_Dw_gtk_viewport_add_anchor      (DwWidget *widget,
+                                                  const gchar* name,
                                                   gint32 y);
 void           p_Dw_gtk_viewport_change_anchor   (DwWidget *widget,
                                                   gchar *name,
Index: src/dw_page.c
===================================================================
RCS file: /sfhome/cvs/dillo/dillo/src/dw_page.c,v
retrieving revision 1.133
diff -p -u -r1.133 dw_page.c
--- src/dw_page.c	17 Oct 2004 13:39:51 -0000	1.133
+++ src/dw_page.c	19 Oct 2004 18:49:50 -0000
@@ -2042,24 +2042,40 @@ void a_Dw_page_add_widget (DwPage *page,
 
 
 /*
- * Add an anchor to the page. name is copied, so no strdup is neccessary for
+ * Add an anchor to the page. "name" is copied, so no strdup is neccessary for
  * the caller.
+ *
+ * Return TRUE on success, and FALSE, when this anchor had already been
+ * added to the widget tree.
  */
-void a_Dw_page_add_anchor (DwPage *page, const char *name, DwStyle *style)
+gboolean a_Dw_page_add_anchor (DwPage *page, const gchar *name, DwStyle *style)
 {
    DwPageWord *word;
+   char *copy;
+   gint32 y;
 
-   word = Dw_page_add_word (page, 0, 0, 0, style);
-   word->content.type = DW_CONTENT_ANCHOR;
-   word->content.data.anchor = g_strdup (name);
-   Dw_page_word_wrap (page, page->num_words - 1);
+   if(page->num_lines == 0)
+      y = 0;
+   else
+      y = Dw_page_line_total_y_offset_i (page, page->num_lines - 1);
 
-   DBG_OBJ_ARRSET_STR (page, "words.%d.content.anchor", page->num_words - 1,
-                       word->content.data.anchor);
+   /*
+    * Since an anchor does not take any space, it is safe to call 
+    * p_Dw_gtk_viewport_add_anchor already here.
+    */
+   if((copy = p_Dw_gtk_viewport_add_anchor (DW_WIDGET(page), name, y)) == NULL)
+      return FALSE;
+   else {
+      word = Dw_page_add_word (page, 0, 0, 0, style);
+      word->content.type = DW_CONTENT_ANCHOR;
+      word->content.data.anchor = copy;
+      Dw_page_word_wrap (page, page->num_words - 1);
+      
+      DBG_OBJ_ARRSET_STR (page, "words.%d.content.anchor", page->num_words - 1,
+                          word->content.data.anchor);
 
-   p_Dw_gtk_viewport_add_anchor
-      (DW_WIDGET(page), word->content.data.anchor,
-      Dw_page_line_total_y_offset_i (page, page->num_lines - 1));
+      return TRUE;
+   }
 }
 
 
Index: src/dw_page.h
===================================================================
RCS file: /sfhome/cvs/dillo/dillo/src/dw_page.h,v
retrieving revision 1.45
diff -p -u -r1.45 dw_page.h
--- src/dw_page.h	13 Mar 2004 17:53:28 -0000	1.45
+++ src/dw_page.h	19 Oct 2004 18:49:51 -0000
@@ -158,7 +158,7 @@ void a_Dw_page_add_text (DwPage *page, c
 void a_Dw_page_add_widget (DwPage *page,
                            DwWidget *widget,
                            DwStyle *style);
-void a_Dw_page_add_anchor (DwPage *page, const char *name, DwStyle *style);
+gboolean a_Dw_page_add_anchor (DwPage *page, const gchar *name, DwStyle *style);
 void a_Dw_page_add_space(DwPage *page, DwStyle *style);
 void a_Dw_page_add_parbreak (DwPage *page, gint space, DwStyle *style);
 void a_Dw_page_add_linebreak (DwPage *page, DwStyle *style);
Index: src/html.c
===================================================================
RCS file: /sfhome/cvs/dillo/dillo/src/html.c,v
retrieving revision 1.217
diff -p -u -r1.217 html.c
--- src/html.c	15 Oct 2004 15:50:41 -0000	1.217
+++ src/html.c	19 Oct 2004 18:50:50 -0000
@@ -2604,7 +2604,9 @@ static void Html_tag_open_a(DilloHtml *h
    if ((attrbuf = Html_get_attr(html, tag, tagsize, "name"))) {
       pname = a_Url_decode_hex_str(attrbuf);
       if (Html_check_name_val(html, pname, "name")) {
-         a_Dw_page_add_anchor(page, pname, html->stack[html->stack_top].style);
+         if(!a_Dw_page_add_anchor(page, pname,
+                                  html->stack[html->stack_top].style))
+            MSG_HTML("Value of 'name' must be unique within the document\n");
          _MSG("Registering ANCHOR: %s\n", pname);
       }
       g_free(pname);
@@ -4494,8 +4496,9 @@ static void Html_process_tag(DilloHtml *
                                        HTML_LeftTrim | HTML_RightTrim)) &&
              Html_check_name_val(html, attrbuf, "id")) {
 
-            a_Dw_page_add_anchor(DW_PAGE (html->dw), attrbuf,
-                                 html->stack[html->stack_top].style);
+            if(!a_Dw_page_add_anchor(DW_PAGE (html->dw), attrbuf,
+                                     html->stack[html->stack_top].style))
+               MSG_HTML("Value of 'id' must be unique within the document\n");
          }
 
          /* let the parser know this was an open tag */