Bug 1773312 - Allow more characters in element/attribute names and prefixes r=smaug,dom-core,devtools-reviewers,ochameau

Implement "relaxed" element/attribute name-validation rules, per:

- whatwg/dom#1079
- whatwg/html#7991
- whatwg/html#11453

That aligns DOM-API name behavior with HTML parser behavior - which has
always allowed a wider range of characters in element and attribute names.

New validation functions in nsContentUtils:

- IsValidElementLocalName(): For createElement - allows [A-Za-z] start followed by
  any char except null/whitespace/>//, or [:_>=0x80] start with restricted continuation
- IsValidAttributeName(): For setAttribute/toggleAttribute/createAttribute -
  no null, whitespace, /, >, or =
- IsValidNamespacePrefix(): For *NS methods - no null, whitespace, /, or >
- IsValidDoctypeName(): For createDocumentType - no null, whitespace, or >
- ParseQualifiedNameRelaxed(): Validates and parses qualified names with relaxed rules

ParseQualifiedNameRelaxed() correctly implements the "strictly split" algorithm
per the DOM spec: for qualified names with multiple colons like "f:o:o", the
local name is just the second token ("o"), not everything after the first colon
("o:o"). This matches the spec's requirement to split on all colons and use only
splitResult[0] as prefix and splitResult[1] as localName.

Deleted outdated DOM Level 1 mochitest tests that tested old XML-based name
validation rules; WPT name-validation.html provides coverage for the new
relaxed rules. Removed WPT expected-failure .ini files, since all tests now pass.

Differential Revision: https://phabricator.services.mozilla.com/D277822

Author: sideshowbarker

devtools/client/inspector/markup/test/browser_markup_tag_edit_01.js

@@ -25,8 +25,8 @@ var TEST_DATA = [
   },
   {
     desc:
-      'Try changing an attribute to a quote (") - this should result ' +
-      "in it being set to an empty string",
+      'Try changing an attribute to a quote (") - class becomes empty, ' +
+      "and the trailing quote becomes a valid attribute name",
     node: "#node22",
     originalAttributes: {
       id: "node22",
@@ -37,6 +37,8 @@ var TEST_DATA = [
     expectedAttributes: {
       id: "node22",
       class: "",
+      // With relaxed attribute name rules, " is now a valid attribute name
+      '"': "",
     },
   },
   {
@@ -63,6 +65,8 @@ var TEST_DATA = [
     expectedAttributes: {
       id: "node24",
       class: "",
+      // With relaxed attribute name rules, " is now a valid attribute name
+      '"': "",
     },
   },
 ];

devtools/client/inspector/markup/test/browser_markup_tag_edit_06.js

@@ -24,10 +24,13 @@ var TEST_DATA = [
     },
   },
   {
-    desc: "Invalid attribute name",
+    desc: "Attribute name starting with <",
     text: "x='y' <why-would-you-do-this>=\"???\"",
     expectedAttributes: {
       x: "y",
+      // HTML parser reads "<why-would-you-do-this" as attr name (> ends tag).
+      // With relaxed rules, < is now valid in attribute names.
+      "<why-would-you-do-this": "",
     },
   },
   {

devtools/client/inspector/markup/test/browser_markup_tag_edit_07.js

@@ -43,12 +43,14 @@ var TEST_DATA = [
   {
     desc:
       'Try add an attribute containing a quote (") attribute by ' +
-      "clicking the empty space after a node - this should result " +
-      "in it being set to an empty string",
+      "clicking the empty space after a node - style becomes empty, " +
+      "and the trailing quote becomes a valid attribute name",
     text: 'class="newclass" style="""',
     expectedAttributes: {
       class: "newclass",
       style: "",
+      // With relaxed attribute name rules, " is now a valid attribute name
+      '"': "",
     },
   },
   {

devtools/client/inspector/markup/test/browser_markup_tag_edit_12.js

@@ -63,7 +63,8 @@ async function testAttributeDeletion(inspector) {
   const attrs = await getAttributesFromEditor("#delattr", inspector);
 
   info("Entering an invalid attribute to delete the attribute");
-  await editAttributeAndTab('"', inspector);
+  // Use > which is still forbidden in attribute names with relaxed rules
+  await editAttributeAndTab(">", inspector);
   checkFocusedAttribute(attrs[2], true);
 
   info("Deleting the last attribute");

dom/base/DOMImplementation.cpp

@@ -52,8 +52,9 @@ already_AddRefed<DocumentType> DOMImplementation::CreateDocumentType(
     return nullptr;
   }
 
-  aRv = nsContentUtils::CheckQName(aQualifiedName);
-  if (aRv.Failed()) {
+  // https://dom.spec.whatwg.org/#dom-domimplementation-createdocumenttype
+  if (!nsContentUtils::IsValidDoctypeName(aQualifiedName)) {
+    aRv.ThrowInvalidCharacterError("Invalid doctype name");
     return nullptr;
   }
 
@@ -79,7 +80,9 @@ nsresult DOMImplementation::CreateDocument(const nsAString& aNamespaceURI,
   if (!aQualifiedName.IsEmpty()) {
     const nsString& qName = PromiseFlatString(aQualifiedName);
     const char16_t* colon;
-    rv = nsContentUtils::CheckQName(qName, true, &colon);
+    // https://dom.spec.whatwg.org/#dom-domimplementation-createdocument
+    rv = nsContentUtils::ParseQualifiedNameRelaxed(qName, nsINode::ELEMENT_NODE,
+                                                   &colon);
     NS_ENSURE_SUCCESS(rv, rv);
 
     if (colon && (DOMStringIsNull(aNamespaceURI) ||

dom/base/Document.cpp

@@ -8997,8 +8997,9 @@ bool IsLowercaseASCII(const nsAString& aValue) {
 already_AddRefed<Element> Document::CreateElement(
     const nsAString& aTagName, const ElementCreationOptionsOrString& aOptions,
     ErrorResult& rv) {
-  rv = nsContentUtils::CheckQName(aTagName, false);
-  if (rv.Failed()) {
+  // https://dom.spec.whatwg.org/#dom-document-createelement
+  if (!nsContentUtils::IsValidElementLocalName(aTagName)) {
+    rv.ThrowInvalidCharacterError("Invalid element name");
     return nullptr;
   }
 
@@ -9075,8 +9076,9 @@ already_AddRefed<Element> Document::CreateElementNS(
 already_AddRefed<Element> Document::CreateXULElement(
     const nsAString& aTagName, const ElementCreationOptionsOrString& aOptions,
     ErrorResult& aRv) {
-  aRv = nsContentUtils::CheckQName(aTagName, false);
-  if (aRv.Failed()) {
+  // https://dom.spec.whatwg.org/#dom-document-createelement
+  if (!nsContentUtils::IsValidElementLocalName(aTagName)) {
+    aRv.ThrowInvalidCharacterError("Invalid element name");
     return nullptr;
   }
 
@@ -9174,9 +9176,9 @@ already_AddRefed<Attr> Document::CreateAttribute(const nsAString& aName,
     return nullptr;
   }
 
-  nsresult res = nsContentUtils::CheckQName(aName, false);
-  if (NS_FAILED(res)) {
-    rv.Throw(res);
+  // https://dom.spec.whatwg.org/#dom-document-createattribute
+  if (!nsContentUtils::IsValidAttributeLocalName(aName)) {
+    rv.ThrowInvalidCharacterError("Invalid attribute name");
     return nullptr;
   }
 
@@ -9188,8 +9190,9 @@ already_AddRefed<Attr> Document::CreateAttribute(const nsAString& aName,
   }
 
   RefPtr<mozilla::dom::NodeInfo> nodeInfo;
-  res = mNodeInfoManager->GetNodeInfo(name, nullptr, kNameSpaceID_None,
-                                      ATTRIBUTE_NODE, getter_AddRefs(nodeInfo));
+  nsresult res =
+      mNodeInfoManager->GetNodeInfo(name, nullptr, kNameSpaceID_None,
+                                    ATTRIBUTE_NODE, getter_AddRefs(nodeInfo));
   if (NS_FAILED(res)) {
     rv.Throw(res);
     return nullptr;
@@ -11827,20 +11830,21 @@ already_AddRefed<Element> Document::CreateElem(const nsAString& aName,
                                                int32_t aNamespaceID,
                                                const nsAString* aIs) {
 #ifdef DEBUG
-  nsAutoString qName;
-  if (aPrefix) {
+  if (!aPrefix) {
+    NS_ASSERTION(nsContentUtils::IsValidElementLocalName(aName),
+                 "Don't pass invalid names to Document::CreateElem");
+  } else {
+    nsAutoString qName;
     aPrefix->ToString(qName);
     qName.Append(':');
-  }
-  qName.Append(aName);
+    qName.Append(aName);
 
-  // Note: "a:b:c" is a valid name in non-namespaces XML, and
-  // Document::CreateElement can call us with such a name and no prefix,
-  // which would cause an error if we just used true here.
-  bool nsAware = aPrefix != nullptr || aNamespaceID != GetDefaultNamespaceID();
-  NS_ASSERTION(NS_SUCCEEDED(nsContentUtils::CheckQName(qName, nsAware)),
-               "Don't pass invalid prefixes to Document::CreateElem, "
-               "check caller.");
+    const char16_t* localNameEnd;
+    const char16_t* colon;
+    NS_ASSERTION(NS_SUCCEEDED(nsContentUtils::ParseQualifiedNameRelaxed(
+                     qName, ELEMENT_NODE, &colon, &localNameEnd)),
+                 "Don't pass invalid prefixes to Document::CreateElem.");
+  }
 #endif
 
   RefPtr<mozilla::dom::NodeInfo> nodeInfo;

dom/base/Element.cpp

@@ -1678,8 +1678,9 @@ bool Element::ToggleAttribute(const nsAString& aName,
                               const Optional<bool>& aForce,
                               nsIPrincipal* aTriggeringPrincipal,
                               ErrorResult& aError) {
-  aError = nsContentUtils::CheckQName(aName, false);
-  if (aError.Failed()) {
+  // https://dom.spec.whatwg.org/#dom-element-toggleattribute
+  if (!nsContentUtils::IsValidAttributeLocalName(aName)) {
+    aError.ThrowInvalidCharacterError("Invalid attribute name");
     return false;
   }
 
@@ -1713,8 +1714,9 @@ bool Element::ToggleAttribute(const nsAString& aName,
 void Element::SetAttribute(const nsAString& aName, const nsAString& aValue,
                            nsIPrincipal* aTriggeringPrincipal,
                            ErrorResult& aError) {
-  aError = nsContentUtils::CheckQName(aName, false);
-  if (aError.Failed()) {
+  // https://dom.spec.whatwg.org/#dom-element-setattribute
+  if (!nsContentUtils::IsValidAttributeLocalName(aName)) {
+    aError.ThrowInvalidCharacterError("Invalid attribute name");
     return;
   }
 
@@ -1838,8 +1840,9 @@ void Element::SetAttribute(
     const nsAString& aName,
     const TrustedHTMLOrTrustedScriptOrTrustedScriptURLOrString& aValue,
     nsIPrincipal* aTriggeringPrincipal, ErrorResult& aError) {
-  aError = nsContentUtils::CheckQName(aName, false);
-  if (aError.Failed()) {
+  // https://dom.spec.whatwg.org/#dom-element-setattribute
+  if (!nsContentUtils::IsValidAttributeLocalName(aName)) {
+    aError.ThrowInvalidCharacterError("Invalid attribute name");
     return;
   }