Tickets #1909 and #2508 involve code which compiles but then

fails at runtime due to invalid bytecode.  This commit turns those
into compile time errors.  Includes negative test case.

git-svn-id: http://lampsvn.epfl.ch/svn-repos/scala/scala/trunk@19247 5e8d7ff9-d8ef-0310-90f0-a4852d11357a

src/compiler/scala/tools/nsc/symtab/Symbols.scala

@@ -521,6 +521,10 @@ trait Symbols {
     /** Does this symbol denote the primary constructor of its enclosing class? */
     final def isPrimaryConstructor =
       isConstructor && owner.primaryConstructor == this
+      
+    /** Does this symbol denote an auxiliary constructor of its enclosing class? */
+    final def isAuxiliaryConstructor =
+      isConstructor && !isPrimaryConstructor
 
     /** Is this symbol a synthetic apply or unapply method in a companion object of a case class? */
     final def isCaseApplyOrUnapply = 

src/compiler/scala/tools/nsc/transform/UnCurry.scala

@@ -485,6 +485,11 @@ abstract class UnCurry extends InfoTransform with TypingTransformers {
       def liftTree(tree: Tree) = {
         if (settings.debug.value)
           log("lifting tree at: " + (tree.pos))
+
+        // Until/unless #1909 is fixed, much better to not compile than to fail at runtime.
+        if (currentOwner.isAuxiliaryConstructor)
+          unit.error(tree.pos, "Implementation restriction: auxiliary constructor calls may not use expressions which require lifting.")
+          
         val sym = currentOwner.newMethod(tree.pos, unit.fresh.newName(tree.pos, "liftedTree"))
         sym.setInfo(MethodType(List(), tree.tpe))
         new ChangeOwnerTraverser(currentOwner, sym).traverse(tree)

test/files/neg/bug1909.check

@@ -0,0 +1,4 @@
+bug1909.scala:5: error: Implementation restriction: auxiliary constructor calls may not use expressions which require lifting.
+  def this(p: String) = this(try 0)
+                             ^
+one error found

test/files/neg/bug1909.scala

@@ -0,0 +1,6 @@
+// Until #1909 is fixed, if this compiles the bytecode
+// will trigger a VerifyError.
+class Class {
+  def this(value: Int) = this()
+  def this(p: String) = this(try 0)
+}