Preserve every HTML child in a Popup

folium/map.py

@@ -615,16 +615,29 @@ class Popup(MacroElement):
     _template = Template("""
         var {{this.get_name()}} = L.popup({{ this.options|tojavascript }});
 
+        {% set multiple = this.html._children|length > 1 %}
+        {% if this.lazy and this.html._children %}
+            {{ this._parent.get_name() }}.once('click', function() {
+        {% endif %}
+        {% if multiple %}
+            var {{ this.get_name() }}_content = document.createElement('div');
+        {% endif %}
         {% for name, element in this.html._children.items() %}
-            {% if this.lazy %}
-                {{ this._parent.get_name() }}.once('click', function() {
-                    {{ this.get_name() }}.setContent($(`{{ element.render(**kwargs).replace('\\n',' ') }}`)[0]);
-                });
+            var {{ name }} = $(`{{ element.render(**kwargs).replace('\\n',' ') }}`)[0];
+            {% if multiple %}
+                if ({{ name }}) {
+                    {{ this.get_name() }}_content.appendChild({{ name }});
+                }
             {% else %}
-                var {{ name }} = $(`{{ element.render(**kwargs).replace('\\n',' ') }}`)[0];
                 {{ this.get_name() }}.setContent({{ name }});
             {% endif %}
         {% endfor %}
+        {% if multiple %}
+            {{ this.get_name() }}.setContent({{ this.get_name() }}_content);
+        {% endif %}
+        {% if this.lazy and this.html._children %}
+            });
+        {% endif %}
 
         {{ this._parent.get_name() }}.bindPopup({{ this.get_name() }})
         {% if this.show %}.openPopup(){% endif %};

tests/test_map.py

@@ -106,6 +106,24 @@ def test_popup_unicode():
     assert "".join(popup.html.render().split()) == "".join(tmpl(**kw).split())
 
 
+@pytest.mark.parametrize("lazy", [False, True])
+def test_popup_multiple_children(lazy):
+    popup = Popup("First", lazy=lazy)
+    popup.html.add_child(Popup("Second").html)
+    marker = Marker([0, 0], popup=popup).add_to(Map(tiles=None))
+    rendered = popup._template.render(this=popup, kwargs={})
+
+    # Setting content once per child discards all but the last child.
+    assert rendered.count(".setContent(") == 1
+    assert "First" in rendered
+    assert "Second" in rendered
+    for name in popup.html._children:
+        assert f"{popup.get_name()}_content.appendChild({name});" in rendered
+    if lazy:
+        assert rendered.count(".once('click'") == 1
+    assert f"{marker.get_name()}.bindPopup({popup.get_name()})" in rendered
+
+
 def test_popup_sticky():
     m = Map()
     popup = Popup("Some text.", sticky=True).add_to(m)