Bug 1795887 - Fix IsValueMissing update for certain input types. r=edgar

Differential Revision: https://phabricator.services.mozilla.com/D159592

dom/html/HTMLInputElement.cpp

@@ -6508,25 +6508,26 @@ void HTMLInputElement::UpdateValueMissingValidityStateForRadio(
 
   HTMLInputElement* selection = GetSelectedRadioButton();
 
-  aIgnoreSelf = aIgnoreSelf || !IsMutable();
-
   // If there is no selection, that might mean the radio is not in a group.
   // In that case, we can look for the checked state of the radio.
   bool selected = selection || (!aIgnoreSelf && mChecked);
   bool required = !aIgnoreSelf && IsRequired();
-  bool valueMissing = false;
 
   nsCOMPtr<nsIRadioGroupContainer> container = GetRadioGroupContainer();
 
-  if (!container) {
-    SetValidityState(VALIDITY_STATE_VALUE_MISSING,
-                     IsMutable() && required && !selected);
-    return;
-  }
-
   nsAutoString name;
   GetAttr(kNameSpaceID_None, nsGkAtoms::name, name);
 
+  if (!container) {
+    // As per the spec, a radio button not within a radio button group cannot
+    // suffer from being missing; however, we currently are failing to get a
+    // radio group in the case of a single, named radio button that has no
+    // form owner, forcing us to check for validity in that case here.
+    SetValidityState(VALIDITY_STATE_VALUE_MISSING,
+                     required && !selected && !name.IsEmpty());
+    return;
+  }
+
   // If the current radio is required and not ignored, we can assume the entire
   // group is required.
   if (!required) {
@@ -6535,8 +6536,7 @@ void HTMLInputElement::UpdateValueMissingValidityStateForRadio(
                    : container->GetRequiredRadioCount(name);
   }
 
-  valueMissing = required && !selected;
-
+  bool valueMissing = required && !selected;
   if (container->GetValueMissingState(name) != valueMissing) {
     container->SetValueMissingState(name, valueMissing);