two version of R2R are hereHEADmaster

1 files changed, 619 insertions, 0 deletions

diff --git a/.venv/lib/python3.12/site-packages/lxml/proxy.pxi b/.venv/lib/python3.12/site-packages/lxml/proxy.pxi
new file mode 100644
index 00000000..f7b47a73
--- /dev/null
+++ b/.venv/lib/python3.12/site-packages/lxml/proxy.pxi
@@ -0,0 +1,619 @@
+# Proxy functions and low level node allocation stuff
+
+# Proxies represent elements, their reference is stored in the C
+# structure of the respective node to avoid multiple instantiation of
+# the Python class.
+
+@cython.linetrace(False)
+@cython.profile(False)
+cdef inline _Element getProxy(xmlNode* c_node):
+    """Get a proxy for a given node.
+    """
+    #print "getProxy for:", <int>c_node
+    if c_node is not NULL and c_node._private is not NULL:
+        return <_Element>c_node._private
+    else:
+        return None
+
+
+@cython.linetrace(False)
+@cython.profile(False)
+cdef inline bint hasProxy(xmlNode* c_node):
+    if c_node._private is NULL:
+        return False
+    return True
+
+
+@cython.linetrace(False)
+@cython.profile(False)
+cdef inline int _registerProxy(_Element proxy, _Document doc,
+                               xmlNode* c_node) except -1:
+    """Register a proxy and type for the node it's proxying for.
+    """
+    #print "registering for:", <int>proxy._c_node
+    assert not hasProxy(c_node), "double registering proxy!"
+    proxy._doc = doc
+    proxy._c_node = c_node
+    c_node._private = <void*>proxy
+    return 0
+
+
+@cython.linetrace(False)
+@cython.profile(False)
+cdef inline int _unregisterProxy(_Element proxy) except -1:
+    """Unregister a proxy for the node it's proxying for.
+    """
+    cdef xmlNode* c_node = proxy._c_node
+    assert c_node._private is <void*>proxy, "Tried to unregister unknown proxy"
+    c_node._private = NULL
+    return 0
+
+
+################################################################################
+# temporarily make a node the root node of its document
+
+cdef xmlDoc* _fakeRootDoc(xmlDoc* c_base_doc, xmlNode* c_node) except NULL:
+    return _plainFakeRootDoc(c_base_doc, c_node, 1)
+
+cdef xmlDoc* _plainFakeRootDoc(xmlDoc* c_base_doc, xmlNode* c_node,
+                               bint with_siblings) except NULL:
+    # build a temporary document that has the given node as root node
+    # note that copy and original must not be modified during its lifetime!!
+    # always call _destroyFakeDoc() after use!
+    cdef xmlNode* c_child
+    cdef xmlNode* c_root
+    cdef xmlNode* c_new_root
+    cdef xmlDoc*  c_doc
+    if with_siblings or (c_node.prev is NULL and c_node.next is NULL):
+        c_root = tree.xmlDocGetRootElement(c_base_doc)
+        if c_root is c_node:
+            # already the root node, no siblings
+            return c_base_doc
+
+    c_doc  = _copyDoc(c_base_doc, 0)                   # non recursive!
+    c_new_root = tree.xmlDocCopyNode(c_node, c_doc, 2) # non recursive!
+    tree.xmlDocSetRootElement(c_doc, c_new_root)
+    _copyParentNamespaces(c_node, c_new_root)
+
+    c_new_root.children = c_node.children
+    c_new_root.last = c_node.last
+    c_new_root.next = c_new_root.prev = NULL
+
+    # store original node
+    c_doc._private = c_node
+
+    # divert parent pointers of children
+    c_child = c_new_root.children
+    while c_child is not NULL:
+        c_child.parent = c_new_root
+        c_child = c_child.next
+
+    c_doc.children = c_new_root
+    return c_doc
+
+cdef void _destroyFakeDoc(xmlDoc* c_base_doc, xmlDoc* c_doc) noexcept:
+    # delete a temporary document
+    cdef xmlNode* c_child
+    cdef xmlNode* c_parent
+    cdef xmlNode* c_root
+    if c_doc is c_base_doc:
+        return
+    c_root = tree.xmlDocGetRootElement(c_doc)
+
+    # restore parent pointers of children
+    c_parent = <xmlNode*>c_doc._private
+    c_child = c_root.children
+    while c_child is not NULL:
+        c_child.parent = c_parent
+        c_child = c_child.next
+
+    # prevent recursive removal of children
+    c_root.children = c_root.last = NULL
+    tree.xmlFreeDoc(c_doc)
+
+cdef _Element _fakeDocElementFactory(_Document doc, xmlNode* c_element):
+    """Special element factory for cases where we need to create a fake
+    root document, but still need to instantiate arbitrary nodes from
+    it.  If we instantiate the fake root node, things will turn bad
+    when it's destroyed.
+
+    Instead, if we are asked to instantiate the fake root node, we
+    instantiate the original node instead.
+    """
+    if c_element.doc is not doc._c_doc:
+        if c_element.doc._private is not NULL:
+            if c_element is c_element.doc.children:
+                c_element = <xmlNode*>c_element.doc._private
+                #assert c_element.type == tree.XML_ELEMENT_NODE
+    return _elementFactory(doc, c_element)
+
+################################################################################
+# support for freeing tree elements when proxy objects are destroyed
+
+cdef int attemptDeallocation(xmlNode* c_node) noexcept:
+    """Attempt deallocation of c_node (or higher up in tree).
+    """
+    cdef xmlNode* c_top
+    # could be we actually aren't referring to the tree at all
+    if c_node is NULL:
+        #print "not freeing, node is NULL"
+        return 0
+    c_top = getDeallocationTop(c_node)
+    if c_top is not NULL:
+        #print "freeing:", c_top.name
+        _removeText(c_top.next) # tail
+        tree.xmlFreeNode(c_top)
+        return 1
+    return 0
+
+cdef xmlNode* getDeallocationTop(xmlNode* c_node) noexcept:
+    """Return the top of the tree that can be deallocated, or NULL.
+    """
+    cdef xmlNode* c_next
+    #print "trying to do deallocating:", c_node.type
+    if hasProxy(c_node):
+        #print "Not freeing: proxies still exist"
+        return NULL
+    while c_node.parent is not NULL:
+        c_node = c_node.parent
+        #print "checking:", c_current.type
+        if c_node.type == tree.XML_DOCUMENT_NODE or \
+               c_node.type == tree.XML_HTML_DOCUMENT_NODE:
+            #print "not freeing: still in doc"
+            return NULL
+        # if we're still attached to the document, don't deallocate
+        if hasProxy(c_node):
+            #print "Not freeing: proxies still exist"
+            return NULL
+    # see whether we have children to deallocate
+    if not canDeallocateChildNodes(c_node):
+        return NULL
+    # see whether we have siblings to deallocate
+    c_next = c_node.prev
+    while c_next:
+        if _isElement(c_next):
+            if hasProxy(c_next) or not canDeallocateChildNodes(c_next):
+                return NULL
+        c_next = c_next.prev
+    c_next = c_node.next
+    while c_next:
+        if _isElement(c_next):
+            if hasProxy(c_next) or not canDeallocateChildNodes(c_next):
+                return NULL
+        c_next = c_next.next
+    return c_node
+
+cdef int canDeallocateChildNodes(xmlNode* c_parent) noexcept:
+    cdef xmlNode* c_node
+    c_node = c_parent.children
+    tree.BEGIN_FOR_EACH_ELEMENT_FROM(c_parent, c_node, 1)
+    if hasProxy(c_node):
+        return 0
+    tree.END_FOR_EACH_ELEMENT_FROM(c_node)
+    return 1
+
+################################################################################
+# fix _Document references and namespaces when a node changes documents
+
+cdef void _copyParentNamespaces(xmlNode* c_from_node, xmlNode* c_to_node) noexcept nogil:
+    """Copy the namespaces of all ancestors of c_from_node to c_to_node.
+    """
+    cdef xmlNode* c_parent
+    cdef xmlNs* c_ns
+    cdef xmlNs* c_new_ns
+    cdef int prefix_known
+    c_parent = c_from_node.parent
+    while c_parent and (tree._isElementOrXInclude(c_parent) or
+                        c_parent.type == tree.XML_DOCUMENT_NODE):
+        c_new_ns = c_parent.nsDef
+        while c_new_ns:
+            # libxml2 will check if the prefix is already defined
+            tree.xmlNewNs(c_to_node, c_new_ns.href, c_new_ns.prefix)
+            c_new_ns = c_new_ns.next
+        c_parent = c_parent.parent
+
+
+ctypedef struct _ns_update_map:
+    xmlNs* old
+    xmlNs* new
+
+
+ctypedef struct _nscache:
+    _ns_update_map* ns_map
+    size_t size
+    size_t last
+
+
+cdef int _growNsCache(_nscache* c_ns_cache) except -1:
+    cdef _ns_update_map* ns_map_ptr
+    if c_ns_cache.size == 0:
+        c_ns_cache.size = 20
+    else:
+        c_ns_cache.size *= 2
+    ns_map_ptr = <_ns_update_map*> python.lxml_realloc(
+        c_ns_cache.ns_map, c_ns_cache.size, sizeof(_ns_update_map))
+    if not ns_map_ptr:
+        python.lxml_free(c_ns_cache.ns_map)
+        c_ns_cache.ns_map = NULL
+        raise MemoryError()
+    c_ns_cache.ns_map = ns_map_ptr
+    return 0
+
+
+cdef inline int _appendToNsCache(_nscache* c_ns_cache,
+                                 xmlNs* c_old_ns, xmlNs* c_new_ns) except -1:
+    if c_ns_cache.last >= c_ns_cache.size:
+        _growNsCache(c_ns_cache)
+    c_ns_cache.ns_map[c_ns_cache.last] = _ns_update_map(old=c_old_ns, new=c_new_ns)
+    c_ns_cache.last += 1
+
+
+cdef int _stripRedundantNamespaceDeclarations(xmlNode* c_element, _nscache* c_ns_cache,
+                                              xmlNs** c_del_ns_list) except -1:
+    """Removes namespace declarations from an element that are already
+    defined in its parents.  Does not free the xmlNs's, just prepends
+    them to the c_del_ns_list.
+    """
+    cdef xmlNs* c_ns
+    cdef xmlNs* c_ns_next
+    cdef xmlNs** c_nsdef
+    # use a xmlNs** to handle assignments to "c_element.nsDef" correctly
+    c_nsdef = &c_element.nsDef
+    while c_nsdef[0] is not NULL:
+        c_ns = tree.xmlSearchNsByHref(
+            c_element.doc, c_element.parent, c_nsdef[0].href)
+        if c_ns is NULL:
+            # new namespace href => keep and cache the ns declaration
+            _appendToNsCache(c_ns_cache, c_nsdef[0], c_nsdef[0])
+            c_nsdef = &c_nsdef[0].next
+        else:
+            # known namespace href => cache mapping and strip old ns
+            _appendToNsCache(c_ns_cache, c_nsdef[0], c_ns)
+            # cut out c_nsdef.next and prepend it to garbage chain
+            c_ns_next = c_nsdef[0].next
+            c_nsdef[0].next = c_del_ns_list[0]
+            c_del_ns_list[0] = c_nsdef[0]
+            c_nsdef[0] = c_ns_next
+    return 0
+
+
+cdef void _cleanUpFromNamespaceAdaptation(xmlNode* c_start_node,
+                                          _nscache* c_ns_cache, xmlNs* c_del_ns_list) noexcept:
+    # Try to recover from exceptions with really bad timing.  We were in the middle
+    # of ripping out xmlNS-es and likely ran out of memory.  Try to fix up the tree
+    # by re-adding the original xmlNs declarations (which might still be used in some
+    # places).
+    if c_ns_cache.ns_map:
+        python.lxml_free(c_ns_cache.ns_map)
+    if c_del_ns_list:
+        if not c_start_node.nsDef:
+            c_start_node.nsDef = c_del_ns_list
+        else:
+            c_ns = c_start_node.nsDef
+            while c_ns.next:
+                c_ns = c_ns.next
+            c_ns.next = c_del_ns_list
+
+
+cdef int moveNodeToDocument(_Document doc, xmlDoc* c_source_doc,
+                            xmlNode* c_element) except -1:
+    """Fix the xmlNs pointers of a node and its subtree that were moved.
+
+    Originally copied from libxml2's xmlReconciliateNs().  Expects
+    libxml2 doc pointers of node to be correct already, but fixes
+    _Document references.
+
+    For each node in the subtree, we do this:
+
+    1) Remove redundant declarations of namespace that are already
+       defined in its parents.
+
+    2) Replace namespaces that are *not* defined on the node or its
+       parents by the equivalent namespace declarations that *are*
+       defined on the node or its parents (possibly using a different
+       prefix).  If a namespace is unknown, declare a new one on the
+       node.
+
+    3) Reassign the names of tags and attribute from the dict of the
+       target document *iff* it is different from the dict used in the
+       source subtree.
+
+    4) Set the Document reference to the new Document (if different).
+       This is done on backtracking to keep the original Document
+       alive as long as possible, until all its elements are updated.
+
+    Note that the namespace declarations are removed from the tree in
+    step 1), but freed only after the complete subtree was traversed
+    and all occurrences were replaced by tree-internal pointers.
+    """
+    cdef xmlNode* c_start_node
+    cdef xmlNode* c_node
+    cdef xmlDoc* c_doc = doc._c_doc
+    cdef tree.xmlAttr* c_attr
+    cdef char* c_name
+    cdef _nscache c_ns_cache = [NULL, 0, 0]
+    cdef xmlNs* c_del_ns_list = NULL
+    cdef proxy_count = 0
+
+    if not tree._isElementOrXInclude(c_element):
+        return 0
+
+    c_start_node = c_element
+
+    tree.BEGIN_FOR_EACH_FROM(c_element, c_element, 1)
+    if tree._isElementOrXInclude(c_element):
+        if hasProxy(c_element):
+            proxy_count += 1
+
+        # 1) cut out namespaces defined here that are already known by
+        #    the ancestors
+        if c_element.nsDef is not NULL:
+            try:
+                _stripRedundantNamespaceDeclarations(c_element, &c_ns_cache, &c_del_ns_list)
+            except:
+                _cleanUpFromNamespaceAdaptation(c_start_node, &c_ns_cache, c_del_ns_list)
+                raise
+
+        # 2) make sure the namespaces of an element and its attributes
+        #    are declared in this document (i.e. on the node or its parents)
+        if c_element.ns is not NULL:
+            _fixCNs(doc, c_start_node, c_element, &c_ns_cache, c_del_ns_list)
+
+        c_node = <xmlNode*>c_element.properties
+        while c_node is not NULL:
+            if c_node.ns is not NULL:
+                _fixCNs(doc, c_start_node, c_node, &c_ns_cache, c_del_ns_list)
+            c_node = c_node.next
+
+    tree.END_FOR_EACH_FROM(c_element)
+
+    # free now unused namespace declarations
+    if c_del_ns_list is not NULL:
+        tree.xmlFreeNsList(c_del_ns_list)
+
+    # cleanup
+    if c_ns_cache.ns_map is not NULL:
+        python.lxml_free(c_ns_cache.ns_map)
+
+    # 3) fix the names in the tree if we moved it from a different thread
+    if doc._c_doc.dict is not c_source_doc.dict:
+        fixThreadDictNames(c_start_node, c_source_doc.dict, doc._c_doc.dict)
+
+    # 4) fix _Document references
+    #    (and potentially deallocate the source document)
+    if proxy_count > 0:
+        if proxy_count == 1 and c_start_node._private is not NULL:
+            proxy = getProxy(c_start_node)
+            if proxy is not None:
+                if proxy._doc is not doc:
+                    proxy._doc = doc
+            else:
+                fixElementDocument(c_start_node, doc, proxy_count)
+        else:
+            fixElementDocument(c_start_node, doc, proxy_count)
+
+    return 0
+
+
+cdef void _setTreeDoc(xmlNode* c_node, xmlDoc* c_doc) noexcept:
+    """Adaptation of 'xmlSetTreeDoc()' that deep-fixes the document links iteratively.
+    It avoids https://gitlab.gnome.org/GNOME/libxml2/issues/42
+    """
+    tree.BEGIN_FOR_EACH_FROM(c_node, c_node, 1)
+    if c_node.type == tree.XML_ELEMENT_NODE:
+        c_attr = <tree.xmlAttr*>c_node.properties
+        while c_attr:
+            if c_attr.atype == tree.XML_ATTRIBUTE_ID:
+                tree.xmlRemoveID(c_node.doc, c_attr)
+            c_attr.doc = c_doc
+            _fixDocChildren(c_attr.children, c_doc)
+            c_attr = c_attr.next
+    # Set doc link for all nodes, not only elements.
+    c_node.doc = c_doc
+    tree.END_FOR_EACH_FROM(c_node)
+
+
+cdef inline void _fixDocChildren(xmlNode* c_child, xmlDoc* c_doc) noexcept:
+    while c_child:
+        c_child.doc = c_doc
+        if c_child.children:
+            _fixDocChildren(c_child.children, c_doc)
+        c_child = c_child.next
+
+
+cdef int _fixCNs(_Document doc, xmlNode* c_start_node, xmlNode* c_node,
+                 _nscache* c_ns_cache, xmlNs* c_del_ns_list) except -1:
+    cdef xmlNs* c_ns = NULL
+    cdef bint is_prefixed_attr = (c_node.type == tree.XML_ATTRIBUTE_NODE and c_node.ns.prefix)
+
+    for ns_map in c_ns_cache.ns_map[:c_ns_cache.last]:
+        if c_node.ns is ns_map.old:
+            if is_prefixed_attr and not ns_map.new.prefix:
+                # avoid dropping prefix from attributes
+                continue
+            c_ns = ns_map.new
+            break
+
+    if c_ns:
+        c_node.ns = c_ns
+    else:
+        # not in cache or not acceptable
+        # => find a replacement from this document
+        try:
+            c_ns = doc._findOrBuildNodeNs(
+                c_start_node, c_node.ns.href, c_node.ns.prefix,
+                c_node.type == tree.XML_ATTRIBUTE_NODE)
+            c_node.ns = c_ns
+            _appendToNsCache(c_ns_cache, c_node.ns, c_ns)
+        except:
+            _cleanUpFromNamespaceAdaptation(c_start_node, c_ns_cache, c_del_ns_list)
+            raise
+    return 0
+
+
+cdef int fixElementDocument(xmlNode* c_element, _Document doc,
+                             size_t proxy_count) except -1:
+    cdef xmlNode* c_node = c_element
+    cdef _Element proxy = None # init-to-None required due to fake-loop below
+    tree.BEGIN_FOR_EACH_FROM(c_element, c_node, 1)
+    if c_node._private is not NULL:
+        proxy = getProxy(c_node)
+        if proxy is not None:
+            if proxy._doc is not doc:
+                proxy._doc = doc
+            proxy_count -= 1
+            if proxy_count == 0:
+                return 0
+    tree.END_FOR_EACH_FROM(c_node)
+
+
+cdef void fixThreadDictNames(xmlNode* c_element,
+                             tree.xmlDict* c_src_dict,
+                             tree.xmlDict* c_dict) noexcept nogil:
+    # re-assign the names of tags and attributes
+    #
+    # this should only be called when the element is based on a
+    # different libxml2 tag name dictionary
+    if c_element.type == tree.XML_DOCUMENT_NODE or \
+            c_element.type == tree.XML_HTML_DOCUMENT_NODE:
+        # may define "xml" namespace
+        fixThreadDictNsForNode(c_element, c_src_dict, c_dict)
+        if c_element.doc.extSubset:
+            fixThreadDictNamesForDtd(c_element.doc.extSubset, c_src_dict, c_dict)
+        if c_element.doc.intSubset:
+            fixThreadDictNamesForDtd(c_element.doc.intSubset, c_src_dict, c_dict)
+        c_element = c_element.children
+        while c_element is not NULL:
+            fixThreadDictNamesForNode(c_element, c_src_dict, c_dict)
+            c_element = c_element.next
+    elif tree._isElementOrXInclude(c_element):
+        fixThreadDictNamesForNode(c_element, c_src_dict, c_dict)
+
+
+cdef inline void _fixThreadDictPtr(const_xmlChar** c_ptr,
+                                   tree.xmlDict* c_src_dict,
+                                   tree.xmlDict* c_dict) noexcept nogil:
+    c_str = c_ptr[0]
+    if c_str and c_src_dict and tree.xmlDictOwns(c_src_dict, c_str):
+        # return value can be NULL on memory error, but we don't handle that here
+        c_str = tree.xmlDictLookup(c_dict, c_str, -1)
+        if c_str:
+            c_ptr[0] = c_str
+
+
+cdef void fixThreadDictNamesForNode(xmlNode* c_element,
+                                    tree.xmlDict* c_src_dict,
+                                    tree.xmlDict* c_dict) noexcept nogil:
+    cdef xmlNode* c_node = c_element
+    tree.BEGIN_FOR_EACH_FROM(c_element, c_node, 1)
+    if c_node.type in (tree.XML_ELEMENT_NODE, tree.XML_XINCLUDE_START):
+        fixThreadDictNamesForAttributes(
+            c_node.properties, c_src_dict, c_dict)
+        fixThreadDictNsForNode(c_node, c_src_dict, c_dict)
+        _fixThreadDictPtr(&c_node.name, c_src_dict, c_dict)
+    elif c_node.type == tree.XML_TEXT_NODE:
+        # libxml2's SAX2 parser interns some indentation space
+        fixThreadDictContentForNode(c_node, c_src_dict, c_dict)
+    elif c_node.type == tree.XML_COMMENT_NODE:
+        pass  # don't touch c_node.name
+    else:
+        _fixThreadDictPtr(&c_node.name, c_src_dict, c_dict)
+    tree.END_FOR_EACH_FROM(c_node)
+
+
+cdef inline void fixThreadDictNamesForAttributes(tree.xmlAttr* c_attr,
+                                                 tree.xmlDict* c_src_dict,
+                                                 tree.xmlDict* c_dict) noexcept nogil:
+    cdef xmlNode* c_child
+    cdef xmlNode* c_node = <xmlNode*>c_attr
+    while c_node is not NULL:
+        if c_node.type not in (tree.XML_TEXT_NODE, tree.XML_COMMENT_NODE):
+            _fixThreadDictPtr(&c_node.name, c_src_dict, c_dict)
+        # libxml2 keeps some (!) attribute values in the dict
+        c_child = c_node.children
+        while c_child is not NULL:
+            fixThreadDictContentForNode(c_child, c_src_dict, c_dict)
+            c_child = c_child.next
+        c_node = c_node.next
+
+
+cdef inline void fixThreadDictContentForNode(xmlNode* c_node,
+                                             tree.xmlDict* c_src_dict,
+                                             tree.xmlDict* c_dict) noexcept nogil:
+    if c_node.content is not NULL and \
+           c_node.content is not <xmlChar*>&c_node.properties:
+        if tree.xmlDictOwns(c_src_dict, c_node.content):
+            # result can be NULL on memory error, but we don't handle that here
+            c_node.content = <xmlChar*>tree.xmlDictLookup(c_dict, c_node.content, -1)
+
+
+cdef inline void fixThreadDictNsForNode(xmlNode* c_node,
+                                        tree.xmlDict* c_src_dict,
+                                        tree.xmlDict* c_dict) noexcept nogil:
+    cdef xmlNs* c_ns = c_node.nsDef
+    while c_ns is not NULL:
+        _fixThreadDictPtr(&c_ns.href, c_src_dict, c_dict)
+        _fixThreadDictPtr(&c_ns.prefix, c_src_dict, c_dict)
+        c_ns = c_ns.next
+
+
+cdef void fixThreadDictNamesForDtd(tree.xmlDtd* c_dtd,
+                                   tree.xmlDict* c_src_dict,
+                                   tree.xmlDict* c_dict) noexcept nogil:
+    cdef xmlNode* c_node
+    cdef tree.xmlElement* c_element
+    cdef tree.xmlAttribute* c_attribute
+    cdef tree.xmlEntity* c_entity
+
+    c_node = c_dtd.children
+    while c_node:
+        if c_node.type == tree.XML_ELEMENT_DECL:
+            c_element = <tree.xmlElement*>c_node
+            if c_element.content:
+                _fixThreadDictPtr(&c_element.content.name, c_src_dict, c_dict)
+                _fixThreadDictPtr(&c_element.content.prefix, c_src_dict, c_dict)
+            c_attribute = c_element.attributes
+            while c_attribute:
+                _fixThreadDictPtr(&c_attribute.defaultValue, c_src_dict, c_dict)
+                _fixThreadDictPtr(&c_attribute.name, c_src_dict, c_dict)
+                _fixThreadDictPtr(&c_attribute.prefix, c_src_dict, c_dict)
+                _fixThreadDictPtr(&c_attribute.elem, c_src_dict, c_dict)
+                c_attribute = c_attribute.nexth
+        elif c_node.type == tree.XML_ENTITY_DECL:
+            c_entity = <tree.xmlEntity*>c_node
+            _fixThreadDictPtr(&c_entity.name, c_src_dict, c_dict)
+            _fixThreadDictPtr(&c_entity.ExternalID, c_src_dict, c_dict)
+            _fixThreadDictPtr(&c_entity.SystemID, c_src_dict, c_dict)
+            _fixThreadDictPtr(<const_xmlChar**>&c_entity.content, c_src_dict, c_dict)
+        c_node = c_node.next
+
+
+################################################################################
+# adopt an xmlDoc from an external libxml2 document source
+
+cdef _Document _adoptForeignDoc(xmlDoc* c_doc, _BaseParser parser=None, bint is_owned=True):
+    """Convert and wrap an externally produced xmlDoc for use in lxml.
+    Assures that all '_private' pointers are NULL to prevent accidental
+    dereference into lxml proxy objects.
+    """
+    if c_doc is NULL:
+        raise ValueError("Illegal document provided: NULL")
+    if c_doc.type not in (tree.XML_DOCUMENT_NODE, tree.XML_HTML_DOCUMENT_NODE):
+        doc_type = c_doc.type
+        if is_owned:
+            tree.xmlFreeDoc(c_doc)
+        raise ValueError(f"Illegal document provided: expected XML or HTML, found {doc_type}")
+
+    cdef xmlNode* c_node = <xmlNode*>c_doc
+
+    if is_owned:
+        tree.BEGIN_FOR_EACH_FROM(<xmlNode*>c_doc, c_node, 1)
+        c_node._private = NULL
+        tree.END_FOR_EACH_FROM(c_node)
+    else:
+        # create a fresh copy that lxml owns
+        c_doc = tree.xmlCopyDoc(c_doc, 1)
+        if c_doc is NULL:
+            raise MemoryError()
+
+    return _documentFactory(c_doc, parser)