Merge pull request #4862 from retronym/ticket/9567

SI-9567 Fix pattern match on 23+ param, method local case class

2 files changed, 16 insertions, 4 deletions

diff --git a/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala b/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala
index 451b72d498..a2afb76b0e 100644
--- a/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala
+++ b/src/compiler/scala/tools/nsc/transform/patmat/MatchTranslation.scala
@@ -504,14 +504,26 @@ trait MatchTranslation {
        */
       def treeMaker(binder: Symbol, binderKnownNonNull: Boolean, pos: Position): TreeMaker = {
         val paramAccessors = binder.constrParamAccessors
+        val numParams = paramAccessors.length
+        def paramAccessorAt(subPatIndex: Int) = paramAccessors(math.min(subPatIndex, numParams - 1))
         // binders corresponding to mutable fields should be stored (SI-5158, SI-6070)
         // make an exception for classes under the scala package as they should be well-behaved,
         // to optimize matching on List
+        val hasRepeated = paramAccessors.lastOption match {
+          case Some(x) => definitions.isRepeated(x)
+          case _ => false
+        }
         val mutableBinders = (
           if (!binder.info.typeSymbol.hasTransOwner(ScalaPackageClass) &&
-              (paramAccessors exists (_.isMutable)))
-            subPatBinders.zipWithIndex.collect{ case (binder, idx) if paramAccessors(idx).isMutable => binder }
-          else Nil
+              (paramAccessors exists (x => x.isMutable || definitions.isRepeated(x)))) {
+
+            subPatBinders.zipWithIndex.flatMap {
+              case (binder, idx) =>
+                val param = paramAccessorAt(idx)
+                if (param.isMutable || (definitions.isRepeated(param) && !aligner.isStar)) binder :: Nil
+                else Nil
+            }
+          } else Nil
         )
 
         // checks binder ne null before chaining to the next extractor
diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala b/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala
index a702b3cdf5..f90e61ff92 100644
--- a/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/PatternTypers.scala
@@ -79,7 +79,7 @@ trait PatternTypers {
       // do not update the symbol if the tree's symbol's type does not define an unapply member
       // (e.g. since it's some method that returns an object with an unapply member)
       val fun         = inPlaceAdHocOverloadingResolution(fun0)(hasUnapplyMember)
-      val caseClass   = fun.tpe.typeSymbol.linkedClassOfClass
+      val caseClass   = companionSymbolOf(fun.tpe.typeSymbol.sourceModule, context)
       val member      = unapplyMember(fun.tpe)
       def resultType  = (fun.tpe memberType member).finalResultType
       def isEmptyType = resultOfMatchingMethod(resultType, nme.isEmpty)()