[gtk-doc] mkhtml2: make id generation work accross chunk boundaries

[Stefan Sauer <stefkost src gnome org>]

commit 18399d6b264b1ce7be15a66003074a75c4996154
Author: Stefan Sauer <ensonic users sf net>
Date:   Mon Apr 16 20:20:07 2018 +0200

    mkhtml2: make id generation work accross chunk boundaries

 gtkdoc/mkhtml2.py |   37 +++++++++++++++++++++++++++----------
 1 files changed, 27 insertions(+), 10 deletions(-)
---
diff --git a/gtkdoc/mkhtml2.py b/gtkdoc/mkhtml2.py
index bd449b4..c1da5a8 100644
--- a/gtkdoc/mkhtml2.py
+++ b/gtkdoc/mkhtml2.py
@@ -233,10 +233,12 @@ def chunk(xml_node, module, depth=0, idx=0, parent=None):
                 xml_node = sub_tree
 
             parent = Node(tag, parent=parent, xml=xml_node, depth=depth,
+                          idx=idx,
                           filename=chunk_name + '.html', anchor=None,
                           **title_args)
         else:
             parent = Node(tag, parent=parent, xml=xml_node, depth=depth,
+                          idx=idx,
                           filename=parent.filename, anchor='#' + chunk_name,
                           **title_args)
 
@@ -1146,25 +1148,40 @@ def generate_footer(ctx):
     return result
 
 
+def get_id_path(node):
+    """ Generate the 'id'.
+    We need to walk up the xml-tree and check the positions for each sibling.
+    When reaching the top of the tree we collect remaining index entries from
+    the chunked-tree.
+    """
+    ix = []
+    xml = node.xml
+    parent = xml.getparent()
+    while parent is not None:
+        children = parent.getchildren()
+        ix.insert(0, str(children.index(xml) + 1))
+        xml = parent
+        parent = xml.getparent()
+    while node is not None:
+        ix.insert(0, str(node.idx + 1))
+        node = node.parent
+
+    return ix
+
+
 def get_id(node):
     xml = node.xml
     node_id = xml.attrib.get('id', None)
     if node_id:
         return node_id
 
+    # TODO: this is moot if nothing links to it, we could also consider to omit
+    # the <a name="$id"></a> tag.
     logging.info('%d: No "id" attribute on "%s", generating one',
                  xml.sourceline, xml.tag)
-    ix = []
-    # Generate the 'id'. We need to walk up the xml-tree and check the positions
-    # for each sibling.
-    parent = xml.getparent()
-    while parent is not None:
-        children = parent.getchildren()
-        ix.insert(0, str(children.index(xml) + 1))
-        xml = parent
-        parent = xml.getparent()
+    ix = get_id_path(node)
     # logging.warning('%s: id indexes: %s', node.filename, str(ix))
-    return 'id-1.' + '.'.join(ix)
+    return 'id-' + '.'.join(ix)
 
 
 def convert_chunk_with_toc(ctx, div_class, title_tag):