avm2: Add IS_QNAME flag to Multiname, improve XML name matching

core/src/avm2/e4x.rs

@@ -1055,14 +1055,18 @@ impl<'gc> E4XNode<'gc> {
             return false;
         }
 
+        // The Multiname is not a QName, so an any name matches everything.
+        // See https://github.com/adobe/avmplus/blob/858d034a3bd3a54d9b70909386435cf4aec81d21/core/Multiname.cpp#L59
+        if name.is_any_name() && !name.is_qname() {
+            return true;
+        }
+
         if !name.is_any_name() && self.local_name() != name.local_name() {
             return false;
         }
 
-        // The Multiname is not a QName, so an any name matches everything.
+        if self.local_name().is_none() {
-        // See https://github.com/adobe/avmplus/blob/858d034a3bd3a54d9b70909386435cf4aec81d21/core/Multiname.cpp#L59
+            return false;
-        if name.is_any_name() && name.namespace_set().len() > 1 {
-            return true;
         }
 
         if name.is_any_namespace() {

core/src/avm2/multiname.rs

@@ -68,6 +68,12 @@ bitflags! {
         const HAS_LAZY_NAME = 1 << 1;
         /// Whether this was a 'MultinameA' - used for XML attribute lookups
         const ATTRIBUTE = 1 << 2;
+
+        /// Represents the XML concept of "qualified name".
+        /// This also distinguishes a QName(x, y) from Multiname(x, [y])
+        /// Basically, marks multinames that come from multinames of kind `(RT)QName(L)(A)`
+        ///   (and dynamically-generated multinames that are supposed to be equivalent to one).
+        const IS_QNAME = 1 << 3;
     }
 }
 
@@ -121,6 +127,15 @@ impl<'gc> Multiname<'gc> {
         self.flags.set(MultinameFlags::ATTRIBUTE, is_attribute);
     }
 
+    #[inline(always)]
+    pub fn is_qname(&self) -> bool {
+        self.flags.contains(MultinameFlags::IS_QNAME)
+    }
+
+    pub fn set_is_qname(&mut self, is_qname: bool) {
+        self.flags.set(MultinameFlags::IS_QNAME, is_qname);
+    }
+
     /// Read a namespace set from the ABC constant pool, and return a list of
     /// copied namespaces.
     pub fn abc_namespace_set(
@@ -175,7 +190,7 @@ impl<'gc> Multiname<'gc> {
                         .pool_string_option(name.0, &mut context.borrow_gc())?
                         .map(|v| v.into()),
                     param: None,
-                    flags: Default::default(),
+                    flags: MultinameFlags::IS_QNAME,
                 }
             }
             AbcMultiname::RTQName { name } | AbcMultiname::RTQNameA { name } => Self {
@@ -184,13 +199,15 @@ impl<'gc> Multiname<'gc> {
                     .pool_string_option(name.0, &mut context.borrow_gc())?
                     .map(|v| v.into()),
                 param: None,
-                flags: MultinameFlags::HAS_LAZY_NS,
+                flags: MultinameFlags::HAS_LAZY_NS | MultinameFlags::IS_QNAME,
             },
             AbcMultiname::RTQNameL | AbcMultiname::RTQNameLA => Self {
                 ns: NamespaceSet::multiple(vec![], mc),
                 name: None,
                 param: None,
-                flags: MultinameFlags::HAS_LAZY_NS | MultinameFlags::HAS_LAZY_NAME,
+                flags: MultinameFlags::HAS_LAZY_NS
+                    | MultinameFlags::HAS_LAZY_NAME
+                    | MultinameFlags::IS_QNAME,
             },
             AbcMultiname::Multiname {
                 namespace_set,
@@ -287,7 +304,7 @@ impl<'gc> Multiname<'gc> {
             ns,
             name,
             param: self.param,
-            flags: self.flags & MultinameFlags::ATTRIBUTE,
+            flags: self.flags & (MultinameFlags::ATTRIBUTE | MultinameFlags::IS_QNAME),
         })
     }
 

tests/tests/swfs/avm2/xml_getdescendants_qname/output.txt

@@ -0,0 +1,21 @@
+getdescendants QName(null, null)
+element
+element
+
+getdescendants Multiname(null, [Namespace("")])
+text
+element
+text
+element
+text
+text
+text
+
+getdescendants Multiname(null, [Namespace(""), Namespace("x")])
+text
+element
+text
+element
+text
+text
+text

tests/tests/swfs/avm2/xml_getdescendants_qname/test.as

@@ -0,0 +1,32 @@
+// compiled with mxmlc, with bytecode modifications in FFDEC
+
+import flash.utils.getQualifiedClassName;
+import flash.utils.getTimer;
+
+class C{
+    public function test(x){
+        trace('getdescendants QName(null, null)')
+        var a = x; // note: put `getdescendants QName(null, null)` here
+        for each(var i in a) { trace(i.nodeKind()); }
+        trace();
+        trace('getdescendants Multiname(null, [Namespace("")])')
+        var b = x; // note: put `getdescendants Multiname(null, [Namespace("")])` here
+        for each(var i in b) { trace(i.nodeKind()); }
+        trace();
+        trace('getdescendants Multiname(null, [Namespace(""), Namespace("x")])')
+        var c = x; // note: put `getdescendants Multiname(null, [Namespace(""), Namespace("x")])` here
+        for each(var i in c) { trace(i.nodeKind()); }
+    }
+}
+XML.ignoreWhitespace = false;
+var s = "<a>   <b>  x  <c>   y </c>  </b> </a>";
+var x = new XML(s);
+new C().test(x);
+
+package {
+    import flash.display.MovieClip;
+    public class Test extends MovieClip {
+        public function Test(){
+        }
+    }
+}

tests/tests/swfs/avm2/xml_getdescendants_qname/test.toml

@@ -0,0 +1 @@
+num_frames = 1