Merge pull request scala#4123 from retronym/ticket/8253

SI-8253 Fix incorrect parsing of <elem xmlns={f("a")}/>

Author: retronym

src/compiler/scala/tools/nsc/ast/parser/SymbolicXMLBuilder.scala

@@ -184,7 +184,8 @@ abstract class SymbolicXMLBuilder(p: Parsers#Parser, preserveWS: Boolean) {
       )
 
       val uri1 = attrMap(z) match {
-        case Apply(_, List(uri @ Literal(Constant(_)))) => mkAssign(uri)
+        case Apply(Select(New(Select(Select(Select(Ident(nme.ROOTPKG), nme.scala_), nme.xml), tpnme.Text)), nme.CONSTRUCTOR), List(uri @ Literal(Constant(_)))) =>
+          mkAssign(uri)
         case Select(_, nme.Nil)                         => mkAssign(const(null))  // allow for xmlns="" -- bug #1626
         case x                                          => mkAssign(x)
       }

src/reflect/scala/reflect/internal/StdNames.scala

@@ -248,6 +248,7 @@ trait StdNames {
     final val Unliftable: NameType          = "Unliftable"
     final val Name: NameType                = "Name"
     final val Tree: NameType                = "Tree"
+    final val Text: NameType                = "Text"
     final val TermName: NameType            = "TermName"
     final val Type : NameType               = "Type"
     final val TypeName: NameType            = "TypeName"
@@ -778,6 +779,7 @@ trait StdNames {
     val values : NameType              = "values"
     val wait_ : NameType               = "wait"
     val withFilter: NameType           = "withFilter"
+    val xml: NameType                  = "xml"
     val zero: NameType                 = "zero"
 
     // quasiquote interpolators:

test/files/run/t8253.check

@@ -0,0 +1,40 @@
+
+<sample xmlns='ns1'/>
+{
+  var $tmpscope: _root_.scala.xml.NamespaceBinding = $scope;
+  $tmpscope = new _root_.scala.xml.NamespaceBinding(null, "ns1", $tmpscope);
+  {
+    val $scope: _root_.scala.xml.NamespaceBinding = $tmpscope;
+    new _root_.scala.xml.Elem(null, "sample", _root_.scala.xml.Null, $scope, true)
+  }
+}
+
+<sample xmlns={identity(ns1)}/>
+{
+  var $tmpscope: _root_.scala.xml.NamespaceBinding = $scope;
+  $tmpscope = new _root_.scala.xml.NamespaceBinding(null, ns1, $tmpscope);
+  {
+    val $scope: _root_.scala.xml.NamespaceBinding = $tmpscope;
+    new _root_.scala.xml.Elem(null, "sample", _root_.scala.xml.Null, $scope, true)
+  }
+}
+
+<sample xmlns:foo='ns1'/>
+{
+  var $tmpscope: _root_.scala.xml.NamespaceBinding = $scope;
+  $tmpscope = new _root_.scala.xml.NamespaceBinding("foo", "ns1", $tmpscope);
+  {
+    val $scope: _root_.scala.xml.NamespaceBinding = $tmpscope;
+    new _root_.scala.xml.Elem(null, "sample", _root_.scala.xml.Null, $scope, true)
+  }
+}
+
+<sample xmlns:foo={identity(ns1)}/>
+{
+  var $tmpscope: _root_.scala.xml.NamespaceBinding = $scope;
+  $tmpscope = new _root_.scala.xml.NamespaceBinding("foo", ns1, $tmpscope);
+  {
+    val $scope: _root_.scala.xml.NamespaceBinding = $tmpscope;
+    new _root_.scala.xml.Elem(null, "sample", _root_.scala.xml.Null, $scope, true)
+  }
+}

test/files/run/t8253.scala

@@ -0,0 +1,14 @@
+object Test extends App {
+  import reflect.runtime.universe._ // not using the XML library in compiler tests
+
+  def show(code: String, t: Tree) = println(s"\n$code\n$t")
+
+  val ns1 = "ns1"
+  show("<sample xmlns='ns1'/>", q"<sample xmlns='ns1'/>")
+  show("<sample xmlns={identity(ns1)}/>", q"<sample xmlns={ns1}/>")
+  show("<sample xmlns:foo='ns1'/>", q"<sample xmlns:foo='ns1'/>")
+  show("<sample xmlns:foo={identity(ns1)}/>", q"<sample xmlns:foo={ns1}/>")
+
+  // `identity(foo)` used to match the overly permissive match in SymbolXMLBuilder
+  // which was intented to more specifically match `_root_.scala.xml.Text(...)`
+}