[FIX] qweb: render a child view with its xmlid

QWeb's get_template:
  * remove the fallback that returned the entire result of IRQweb's
    `load` if no match was made between the t-name of the first children
    of this result and the template to render
  * When get_template receives an etree, directly return it and don't
    try to find a matching t-name in it. The loader was not called but
    a matching was trying to be made, now that we removed the fallback
    a lot of tests that were relying on passing etree didn't work
    anymore.

IRQweb's load now return consistently the full result of IrUiView's
`read_templace` when asked to load an id or an xmlid. We make a special
case to patch the result if asked with an id or with a child view so
that the "t-name" of one of the first children of what we return is
always what QWeb is looking for.

addons/website/tests/test_views.py

@@ -195,7 +195,7 @@ class TestViewSaving(common.TransactionCase):
     def test_save_escaped_text(self):
         """ Test saving html special chars in text nodes """
         view = self.env['ir.ui.view'].create({
-            'arch': '<t><p><h1>hello world</h1></p></t>',
+            'arch': '<t t-name="dummy"><p><h1>hello world</h1></p></t>',
             'type': 'qweb'
         })
         # script and style text nodes should not escaped client side

odoo/addons/base/ir/ir_qweb/ir_qweb.py

@@ -77,18 +77,26 @@ class IrQWeb(models.AbstractModel, QWeb):
         env = self.env
         if lang != env.context.get('lang'):
             env = env(context=dict(env.context, lang=lang))
+
         template = env['ir.ui.view'].read_template(name)
 
-        res_id = isinstance(name, (int, long)) and name or None
-        if res_id:
+        # QWeb's `read_template` will check if one of the first children of
+        # what we send to it has a "t-name" attribute having `name` as value
+        # to consider it has found it. As it'll never be the case when working
+        # with view ids or children view, force it here.
+        def is_child_view(view):
+            view_id = self.env['ir.ui.view'].get_view_id(name)
+            view = self.env['ir.ui.view'].browse(view_id)
+            return view.inherit_id is not None and view.mode != 'primary'
+
+        if isinstance(name, (int, long)) or is_child_view(name):
             for node in etree.fromstring(template):
                 if node.get('t-name'):
-                    return node
-                elif res_id and node.tag == "t":
-                    node.set('t-name', str(res_id))
-                    return node
-
-        return template
+                    node.set('t-name', str(name))
+                    return node.getparent()
+            return None  # trigger "template not found" in QWeb
+        else:
+            return template
 
     # order
 

odoo/addons/base/ir/ir_qweb/qweb.py

@@ -335,6 +335,7 @@ class QWeb(object):
         if isinstance(template, etree._Element):
             document = template
             template = etree.tostring(template)
+            return (document, template)
         else:
             try:
                 document = options.get('load', self.load)(template, options)
@@ -352,9 +353,8 @@ class QWeb(object):
             else:
                 element = etree.parse(document).getroot()
             for node in element:
-                if node.get('t-name') == template:
+                if node.get('t-name') == str(template):
                     return (node, document)
-            return (element, document)
 
         raise QWebException("Template not found", name=template)