It's now possible to override a TreeBuilder's cdata_list_attributes dictionary by passing in a replacement. None will disable the feature altogether. [bug=1832978]

1 files changed, 19 insertions, 4 deletions

diff --git a/bs4/element.py b/bs4/element.py
index 547b8ba..1183f77 100644
--- a/bs4/element.py
+++ b/bs4/element.py
@@ -861,12 +861,27 @@ class Tag(PageElement):
         self.setup(parent, previous)
         self.hidden = False
 
-        # Set up any substitutions, such as the charset in a META tag.
-        if builder is not None:
+        if builder is None:
+            # In the absence of a TreeBuilder, assume this tag is nothing
+            # special.
+            self.can_be_empty_element = False
+            self.cdata_list_attributes = None
+        else:
+            # Set up any substitutions for this tag, such as the charset in a META tag.
             builder.set_up_substitutions(self)
+
+            # Ask the TreeBuilder whether this tag might be an empty-element tag.
             self.can_be_empty_element = builder.can_be_empty_element(name)
-        else:
-            self.can_be_empty_element = False
+
+            # Keep track of the list of attributes of this tag that
+            # might need to be treated as a list.
+            #
+            # For performance reasons, we store the whole data structure
+            # rather than asking the question of every tag. Asking would
+            # require building a new data structure every time, and
+            # (unlike can_be_empty_element), we almost never need
+            # to check this.
+            self.cdata_list_attributes = builder.cdata_list_attributes
             
     parserClass = _alias("parser_class")  # BS3