Corrected the use of special string container classes in cases when a

  single tag may contain strings with different containers; such as
  the <template> tag, which may contain both TemplateString objects
  and Comment objects. [bug=1913406]

3 files changed, 19 insertions, 3 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 93c59ba..288a276 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -7,6 +7,11 @@
 * Performance improvement when processing tags that speeds up overall
   tree construction by 2%. Patch by Morotti. [bug=1899358]
 
+* Corrected the use of special string container classes in cases when a
+  single tag may contain strings with different containers; such as
+  the <template> tag, which may contain both TemplateString objects
+  and Comment objects. [bug=1913406]
+
 * Added a second way to pass specify encodings to UnicodeDammit and
   EncodingDetector, based on the order of precedence defined in the
   HTML5 spec, starting at:
diff --git a/bs4/__init__.py b/bs4/__init__.py
index 3714d67..7c6044a 100644
--- a/bs4/__init__.py
+++ b/bs4/__init__.py
@@ -497,7 +497,7 @@ class BeautifulSoup(Tag):
 
         # On top of that, we may be inside a tag that needs a special
         # container class.
-        if self.string_container_stack:
+        if self.string_container_stack and container is NavigableString:
             container = self.builder.string_containers.get(
                 self.string_container_stack[-1].name, container
             )
diff --git a/bs4/tests/test_tree.py b/bs4/tests/test_tree.py
index 2246346..1bd1577 100644
--- a/bs4/tests/test_tree.py
+++ b/bs4/tests/test_tree.py
@@ -1911,14 +1911,25 @@ class TestNavigableStringSubclasses(SoupTest):
         soup = self.soup(
             "<template>Some text<p>In a tag</p></template>Some text outside"
         )
-        assert all(isinstance(x, TemplateString) for x in soup.template.strings)
-
+        assert all(
+            isinstance(x, TemplateString)
+            for x in soup.template._all_strings(types=None)
+        )
+        
         # Once the <template> tag closed, we went back to using
         # NavigableString.
         outside = soup.template.next_sibling
         assert isinstance(outside, NavigableString)
         assert not isinstance(outside, TemplateString)
 
+        # The TemplateString is also unusual because it can contain
+        # NavigableString subclasses of _other_ types, such as
+        # Comment.
+        markup = b"<template>Some text<p>In a tag</p><!--with a comment--></template>"
+        soup = self.soup(markup)
+        self.assertEqual(markup, soup.template.encode("utf8"))
+
+        
 class TestSoupSelector(TreeTest):
 
     HTML = """