Allow more characters when creating various nodes

Stop using XML grammar productions for validating element, attribute, and doctype names. These were overly-restrictive, as it is possible to create nodes with names that don't match those productions using the HTML parser. After this change, each construct has its own custom name validation algorithm.

The only remaining dependency on XML naming rules is for processing instructions, which are uncommon and cannot be created with the HTML parser anyway.

Closes #769. Closes #849. Closes #1373.

Author: domenic

dom.bs

@@ -12,14 +12,9 @@ Indent: 1
 </pre>
 
 <pre class=anchors>
-urlPrefix: https://www.w3.org/TR/xml/#NT-
- type: type
-  text: Name; url: Name
-  text: Char; url: Char
-  text: PubidChar; url: PubidChar
-urlPrefix: https://www.w3.org/TR/xml-names/#NT-
- type: type
-  text: QName; url: QName
+urlPrefix: https://www.w3.org/TR/xml/#NT-; spec: XML
+ type: dfn
+  text: Name; url: Name; for: XML
 url: https://w3c.github.io/DOM-Parsing/#dom-range-createcontextualfragment
  type: method; text: createContextualFragment(); for: Range
 type: interface
@@ -177,19 +172,64 @@ first <a>following</a> <a for=tree>sibling</a> or null if it has no <a for=tree>
 added.
 
 
-<h3 id=namespaces>Namespaces</h3>
+<h3 id=namespaces>Name validation</h3>
 
-<p>To <dfn export>validate</dfn> a <var>qualifiedName</var>, <a>throw</a> an
-"{{InvalidCharacterError!!exception}}" {{DOMException}} if <var>qualifiedName</var> does not match
-the <code><a type>QName</a></code> production.
+<p>A [=string=] is a <dfn>valid namespace prefix</dfn> if its [=string/length=] is at least 1 and it
+does not contain [=ASCII whitespace=], U+0000 NULL, U+002F (/), or U+003E (>).
 
-<p>To <dfn export>validate and extract</dfn> a <var>namespace</var> and <var>qualifiedName</var>,
-run these steps:
+<p>A [=string=] is a <dfn>valid attribute local name</dfn> if its [=string/length=] is at least 1
+and it does not contain [=ASCII whitespace=], U+0000 NULL, U+002F (/), U+003D (=), or U+003E (>).
+
+<p>A [=string=] |name| is a <dfn>valid element local name</dfn> if the following steps return true:
 
 <ol>
- <li><p>If <var>namespace</var> is the empty string, then set it to null.
+ <li><p>If |name|'s [=string/length=] is 0, then return false.
+
+ <li>
+  <p>If |name|'s 0th [=code point=] is an [=ASCII alpha=], then:
+
+  <ol>
+   <li><p>If |name| contains [=ASCII whitespace=], U+0000 NULL, U+002F (/), or U+003E (>), then
+   return false.
+
+   <li><p>Return true.
+  </ol>
+
+ <li><p>If |name|'s 0th [=code point=] is not U+003A (:), U+005F (_), or in the range U+0080
+ to U+10FFFF, inclusive, then return false.
+
+ <li><p>If |name|'s subsequent [=code points=], if any, are not [=ASCII alphas=], [=ASCII digits=],
+ U+002D (-), U+002E (.), U+003A (:), U+005F (_), or in the range U+0080 to U+10FFFF, inclusive, then
+ return false.
+
+ <li><p>Return true.
+</ol>
+
+<p class=note>This concept is used to validate [=/element=] [=Element/local names=], when
+constructed by DOM APIs. The intention is to allow any name that is possible to construct using the
+HTML parser (the branch where the first [=code point=] is an [=ASCII alpha=]), plus some additional
+possibilities. For those additional possibilities, the ASCII range is restricted for historical
+reasons, but beyond ASCII anything is allowed.
+
+<div class=note>
+ <p>The following JavaScript-compatible regular expression is an implementation of
+ [=valid element local name=]:
+
+ <pre><code class=lang-javascript>
+  /^(?:[A-Za-z][^\0\t\n\f\r\u0020/>]*|[:_\u0080-\u{10FFFF}][A-Za-z0-9-.:_\u0080-\u{10FFFF}]*)$/u
+ </code></pre>
+</div>
+
+<p>A [=string=] is a <dfn>valid doctype name</dfn> if it does not contain [=ASCII whitespace=],
+U+0000 NULL, or U+003E (>).
 
- <li><p><a>Validate</a> <var>qualifiedName</var>.
+<p class="note">The empty string is a [=valid doctype name=].
+
+<p>To <dfn>validate and extract</dfn> a <var>namespace</var> and <var>qualifiedName</var>, given a
+<var>context</var>:
+
+<ol>
+ <li><p>If <var>namespace</var> is the empty string, then set it to null.
 
  <li><p>Let <var>prefix</var> be null.
 
@@ -207,6 +247,15 @@ run these steps:
    <li><p>Set <var>localName</var> to <var>splitResult</var>[1].
   </ol>
 
+ <li><p>If <var>prefix</var> is not a [=valid namespace prefix=], then [=throw=] an
+ "{{InvalidCharacterError}}" {{DOMException}}.
+
+ <li><p>If <var>context</var> is "<code>attribute</code>" and <var>localName</var> is not a
+ [=valid attribute local name=], then [=throw=] an "{{InvalidCharacterError}}" {{DOMException}}.
+
+ <li><p>If <var>context</var> is "<code>element</code>" and <var>localName</var> is not a
+ [=valid element local name=], then [=throw=] an "{{InvalidCharacterError}}" {{DOMException}}.
+
  <li><p>If <var>prefix</var> is non-null and <var>namespace</var> is null, then <a>throw</a> a
  "{{NamespaceError!!exception}}" {{DOMException}}.
 
@@ -221,9 +270,20 @@ run these steps:
  nor <var>prefix</var> is "<code>xmlns</code>", then <a>throw</a> a "{{NamespaceError!!exception}}"
  {{DOMException}}.
 
- <li><p>Return <var>namespace</var>, <var>prefix</var>, and <var>localName</var>.
+ <li><p>Return (<var>namespace</var>, <var>prefix</var>, <var>localName</var>).
 </ol>
 
+<div class="note">
+ <p>Various APIs in this specification used to validate namespace prefixes, attribute local names,
+ element local names, and doctype names more strictly. This was done in a way that aligned with
+ various XML-related specifications. (Although not all rules from the those specifications were
+ enforced.)
+
+ <p>This was found to be annoying for web developers, especially since it meant there were some
+ names that could be created by the HTML parser, but not by DOM APIs. So, the validations have been
+ loosened to just those described above.
+</div>
+
 
 
 <h2 id=events>Events</h2>
@@ -5633,8 +5693,8 @@ method steps are to return the <a>list of elements with class names <var>classNa
   <p>When supplied, <var>options</var>'s {{ElementCreationOptions/is}} can be used to create a
   <a>customized built-in element</a>.
 
-  <p>If <var>localName</var> does not match the <code><a type>Name</a></code> production an
-  "{{InvalidCharacterError!!exception}}" {{DOMException}} will be thrown.
+  <p>If <var>localName</var> is not a <a>valid element local name</a> an
+  "{{InvalidCharacterError}}" {{DOMException}} will be thrown.
 
   <p>When both <var>options</var>'s {{ElementCreationOptions/customElementRegistry}} and
   <var>options</var>'s {{ElementCreationOptions/is}} are supplied, a
@@ -5654,8 +5714,9 @@ method steps are to return the <a>list of elements with class names <var>classNa
   <p>When supplied, <var>options</var>'s {{ElementCreationOptions/is}} can be used to create a
   <a>customized built-in element</a>.
 
-  <p>If <var>qualifiedName</var> does not match the <code><a type>QName</a></code> production an
-  "{{InvalidCharacterError!!exception}}" {{DOMException}} will be thrown.
+  <p>If <var>qualifiedName</var> is not a (possibly-prefixed)
+  <a>valid element local name</a> an "{{InvalidCharacterError}}" {{DOMException}} will be
+  thrown.
 
   <p>If one of the following conditions is true a "{{NamespaceError!!exception}}" {{DOMException}}
   will be thrown:
@@ -5700,8 +5761,7 @@ method steps are to return the <a>list of elements with class names <var>classNa
   <a for=/>node</a> whose
   <a for=ProcessingInstruction>target</a> is <var>target</var> and
   <a for=CharacterData>data</a> is <var>data</var>.
-  If <var>target</var> does not match the
-  <code><a type>Name</a></code> production an
+  If <var>target</var> does not match the <code>[=XML/Name=]</code> production an
   "{{InvalidCharacterError!!exception}}" {{DOMException}} will be thrown.
   If <var>data</var> contains "<code>?></code>" an
   "{{InvalidCharacterError!!exception}}" {{DOMException}} will be thrown.
@@ -5718,7 +5778,7 @@ method steps are to return the <a>list of elements with class names <var>classNa
 method steps are:
 
 <ol>
- <li><p>If <var>localName</var> does not match the <code><a type>Name</a></code> production, then
+ <li><p>If <var>localName</var> is not a <a>valid element local name</a>, then
  <a>throw</a> an "{{InvalidCharacterError!!exception}}" {{DOMException}}.
 
  <li><p>If <a>this</a> is an <a>HTML document</a>, then set <var>localName</var> to
@@ -5739,8 +5799,9 @@ method steps are:
 <var>namespace</var>, <var>qualifiedName</var>, and <var>options</var>, are as follows:
 
 <ol>
- <li><p>Let <var>namespace</var>, <var>prefix</var>, and <var>localName</var> be the result of
- passing <var>namespace</var> and <var>qualifiedName</var> to <a>validate and extract</a>.
+ <li><p>Let (<var>namespace</var>, <var>prefix</var>, <var>localName</var>) be the result of
+ [=validate and extract|validating and extracting=] <var>namespace</var> and
+ <var>qualifiedName</var> given "<code>element</code>".
 
  <li><p>Let <var>registry</var> and <var>is</var> be the result of
  <a>flattening element creation options</a> given <var>options</var> and <a>this</a>.
@@ -5795,9 +5856,6 @@ return a new {{DocumentFragment}} <a for=/>node</a> whose <a for=Node>node docum
 to return a new {{Text}} <a for=/>node</a> whose <a for=CharacterData>data</a> is <var>data</var>
 and <a for=Node>node document</a> is <a>this</a>.
 
-<p class=note>No check is performed that <var>data</var> consists of
-characters that match the <code><a type>Char</a></code> production.
-
 <p>The <dfn method for=Document><code>createCDATASection(<var>data</var>)</code></dfn> method steps
 are:
 
@@ -5816,18 +5874,13 @@ are:
 to return a new {{Comment}} <a for=/>node</a> whose <a for=CharacterData>data</a> is <var>data</var>
 and <a for=Node>node document</a> is <a>this</a>.
 
-<p class=note>No check is performed that <var>data</var> consists of
-characters that match the <code><a type>Char</a></code> production
-or that it contains two adjacent hyphens or ends with a hyphen.
-
 <p>The
 <dfn method for=Document><code>createProcessingInstruction(<var>target</var>, <var>data</var>)</code></dfn>
 method steps are:
 
 <ol>
  <li>If <var>target</var> does not match the
- <!--<code data-anolis-type>PITarget</code>-->
- <code><a type>Name</a></code> production,
+ <code>[=XML/Name=]</code> production,
  then <a>throw</a> an "{{InvalidCharacterError!!exception}}" {{DOMException}}. <!-- DOM3 does not check for "xml" -->
 
  <li>If <var>data</var> contains the string
@@ -5841,11 +5894,6 @@ method steps are:
  <a for=Node>node document</a> set to <a>this</a>.
 </ol>
 
-<p class=note>No check is performed that <var>target</var> contains
-"<code>xml</code>" or "<code>:</code>", or that
-<var>data</var> contains characters that match the
-<code><a type>Char</a></code> production.
-
 <hr>
 
 <dl class=domintro>
@@ -5972,8 +6020,8 @@ these steps:
 steps are:
 
 <ol>
- <li><p>If <var>localName</var> does not match the <code><a type>Name</a></code> production in XML,
- then <a>throw</a> an "{{InvalidCharacterError!!exception}}" {{DOMException}}.
+ <li><p>If <var>localName</var> is not a <a>valid attribute local name</a>, then
+ <a>throw</a> an "{{InvalidCharacterError!!exception}}" {{DOMException}}.
 
  <li>If <a>this</a> is an <a>HTML document</a>, then set <var>localName</var> to
  <var>localName</var> in <a>ASCII lowercase</a>.
@@ -5987,8 +6035,9 @@ steps are:
 method steps are:
 
 <ol>
- <li><p>Let <var>namespace</var>, <var>prefix</var>, and <var>localName</var> be the result of
- passing <var>namespace</var> and <var>qualifiedName</var> to <a>validate and extract</a>.
+ <li><p>Let (<var>namespace</var>, <var>prefix</var>, <var>localName</var>) be the result of
+ [=validate and extract|validating and extracting=] <var>namespace</var> and
+ <var>qualifiedName</var> given "<code>attribute</code>".
 
  <li><p>Return a new <a>attribute</a> whose <a for=Attr>namespace</a> is <var>namespace</var>,
  <a for=Attr>namespace prefix</a> is <var>prefix</var>, <a for=Attr>local name</a> is
@@ -6117,7 +6166,7 @@ created and associate it with that <a for=/>document</a>.
 <pre class=idl>
 [Exposed=Window]
 interface DOMImplementation {
-  [NewObject] DocumentType createDocumentType(DOMString qualifiedName, DOMString publicId, DOMString systemId);
+  [NewObject] DocumentType createDocumentType(DOMString name, DOMString publicId, DOMString systemId);
   [NewObject] XMLDocument createDocument(DOMString? namespace, [LegacyNullToEmptyString] DOMString qualifiedName, optional DocumentType? doctype = null);
   [NewObject] Document createHTMLDocument(optional DOMString title);
 
@@ -6126,16 +6175,12 @@ interface DOMImplementation {
 </pre>
 
 <dl class=domintro>
- <dt><code><var>doctype</var> = <var>document</var> . {{Document/implementation}} . {{createDocumentType(qualifiedName, publicId, systemId)}}</code>
+ <dt><code><var>doctype</var> = <var>document</var> . {{Document/implementation}} . {{createDocumentType(name, publicId, systemId)}}</code>
 
  <dd>
-  Returns a <a>doctype</a>, with the given
-  <var>qualifiedName</var>, <var>publicId</var>, and
-  <var>systemId</var>. If <var>qualifiedName</var> does not
-  match the <code><a type>Name</a></code> production, an
-  "{{InvalidCharacterError!!exception}}" {{DOMException}} is thrown, and if it does not match the
-  <code><a type>QName</a></code> production, a
-  "{{NamespaceError!!exception}}" {{DOMException}} is thrown.
+  Returns a <a>doctype</a>, with the given <var>name</var>, <var>publicId</var>, and <var>systemId</var>.
+
+  If <var>name</var> is not a <a>valid doctype name</a>, an "{{InvalidCharacterError}}" {{DOMException}} is thrown.
 
  <dt><code><var>doc</var> = <var>document</var> . {{Document/implementation}} . <a method for=DOMImplementation lt=createDocument()>createDocument(<var>namespace</var>, <var>qualifiedName</var> [, <var>doctype</var> = null])</a></code>
 
@@ -6164,22 +6209,19 @@ interface DOMImplementation {
 <div class=impl>
 
 <p>The
-<dfn method for=DOMImplementation><code>createDocumentType(<var>qualifiedName</var>, <var>publicId</var>, <var>systemId</var>)</code></dfn>
+<dfn method for=DOMImplementation><code>createDocumentType(<var>name</var>, <var>publicId</var>, <var>systemId</var>)</code></dfn>
 method steps are:
 
 <ol>
- <li><p><a>Validate</a> <var>qualifiedName</var>.
+ <li><p>If <var>name</var> is not a <a>valid doctype name</a>, then throw an "{{InvalidCharacterError}}"
+ {{DOMException}}.
 
- <li><p>Return a new <a>doctype</a>, with <var>qualifiedName</var> as its
+ <li><p>Return a new <a>doctype</a>, with <var>name</var> as its
  <a for=DocumentType>name</a>, <var>publicId</var> as its <a>public ID</a>, and <var>systemId</var>
  as its <a>system ID</a>, and with its <a for=Node>node document</a> set to the associated
  <a for=/>document</a> of <a>this</a>.
 </ol>
 
-<p class=note>No check is performed that <var>publicId</var> code points match the
-<code><a type>PubidChar</a></code> production or that <var>systemId</var> does not contain both a
-'<code>"</code>' and a "<code>'</code>".
-
 <p>The
 <dfn method for=DOMImplementation><code>createDocument(<var>namespace</var>, <var>qualifiedName</var>, <var>doctype</var>)</code></dfn>
 method steps are:
@@ -7284,8 +7326,14 @@ method steps are:
 method steps are:
 
 <ol>
- <li><p>If <var>qualifiedName</var> does not match the <code><a type>Name</a></code> production in
- XML, then <a>throw</a> an "{{InvalidCharacterError!!exception}}" {{DOMException}}.
+ <li>
+  <p>If <var>qualifiedName</var> is not a <a>valid attribute local name</a>, then <a>throw</a> an
+  "{{InvalidCharacterError!!exception}}" {{DOMException}}.
+
+  <p class="note" id="node-setAttribute-qualifiedName">Despite the parameter naming,
+  <var>qualifiedName</var> is only used as a [=Attr/qualified name=] if an [=attribute=] already
+  exists with that qualified name. Otherwise, it is used as the [=Attr/local name=] of the new
+  attribute. We only need to validate it for the latter case.
 
  <li><p>If <a>this</a> is in the <a>HTML namespace</a> and its <a for=Node>node document</a> is an
  <a>HTML document</a>, then set <var>qualifiedName</var> to <var>qualifiedName</var> in
@@ -7309,8 +7357,9 @@ method steps are:
 method steps are:
 
 <ol>
- <li><p>Let <var>namespace</var>, <var>prefix</var>, and <var>localName</var> be the result of
- passing <var>namespace</var> and <var>qualifiedName</var> to <a>validate and extract</a>.
+ <li><p>Let (<var>namespace</var>, <var>prefix</var>, <var>localName</var>) be the result of
+ [=validate and extract|validating and extracting=] <var>namespace</var> and
+ <var>qualifiedName</var> given "<code>element</code>".
 
  <li><p><a>Set an attribute value</a> for <a>this</a> using <var>localName</var>, <var>value</var>,
  and also <var>prefix</var> and <var>namespace</var>.
@@ -7343,8 +7392,12 @@ steps are:
 method steps are:
 
 <ol>
- <li><p>If <var>qualifiedName</var> does not match the <code><a type>Name</a></code> production in
- XML, then <a>throw</a> an "{{InvalidCharacterError!!exception}}" {{DOMException}}.
+ <li>
+  <p>If <var>qualifiedName</var> is not a <a>valid attribute local name</a>, then <a>throw</a> an
+  "{{InvalidCharacterError!!exception}}" {{DOMException}}.
+
+  <p class="note">See <a href="#node-setAttribute-qualifiedName">the discussion above</a> about why
+  we validate it as a local name, instead of a qualified name.
 
  <li><p>If <a>this</a> is in the <a>HTML namespace</a> and its <a for=Node>node document</a> is an
  <a>HTML document</a>, then set <var>qualifiedName</var> to <var>qualifiedName</var> in