Raise TALError when tal:content is used on an HTML tag that must be empty.

lib/python/TAL/HTMLTALParser.py

@@ -142,6 +142,10 @@ class HTMLTALParser(HTMLParser):
         self.scan_xmlns(attrs)
         tag, attrlist, taldict, metaldict, i18ndict \
              = self.process_ns(tag, attrs)
+        if tag in EMPTY_HTML_TAGS and taldict.get("content"):
+            raise TALError(
+                "empty HTML tags cannot use tal:content: %s" % `tag`,
+                self.getpos())
         self.tagstack.append(tag)
         self.gen.emitStartElement(tag, attrlist, taldict, metaldict, i18ndict,
                                   self.getpos())
@@ -154,6 +158,10 @@ class HTMLTALParser(HTMLParser):
         tag, attrlist, taldict, metaldict, i18ndict \
              = self.process_ns(tag, attrs)
         if taldict.get("content"):
+            if tag in EMPTY_HTML_TAGS:
+                raise TALError(
+                    "empty HTML tags cannot use tal:content: %s" % `tag`,
+                    self.getpos())
             self.gen.emitStartElement(tag, attrlist, taldict, metaldict,
                                       i18ndict, self.getpos())
             self.gen.emitEndElement(tag, implied=-1)

lib/python/TAL/tests/test_htmltalparser.py

@@ -478,6 +478,8 @@ class TALGeneratorTestCases(TestCaseBase):
         self._should_error("<p tal:foobar='x' />")
         self._should_error("<p tal:replace='x' tal:content='x' />")
         self._should_error("<p tal:replace='x'>")
+        for tag in HTMLTALParser.EMPTY_HTML_TAGS:
+            self._should_error("<%s tal:content='string:foo'>" % tag)
 
     def check_metal_errors(self):
         exc = METALError