1 files changed, 12 insertions, 11 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala
index 452957745a..80d628d7ac 100644
--- a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala
@@ -109,9 +109,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
   import definitions._
   import analyzer._ //Typer
 
-
-  case class DefaultOverrideMatchAttachment(default: Tree)
-
   object vpmName {
     val one       = newTermName("one")
     val drop      = newTermName("drop")
@@ -222,11 +219,11 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
     // However this is a pain (at least the way I'm going about it)
     // and I have to think these detailed errors are primarily useful
     // for beginners, not people writing nested pattern matches.
-    def checkMatchVariablePatterns(m: Match) {
+    def checkMatchVariablePatterns(cases: List[CaseDef]) {
       // A string describing the first variable pattern
       var vpat: String = null
       // Using an iterator so we can recognize the last case
-      val it = m.cases.iterator
+      val it = cases.iterator
 
       def addendum(pat: Tree) = {
         matchingSymbolInScope(pat) match {
@@ -269,7 +266,15 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
       */
     def translateMatch(match_ : Match): Tree = {
       val Match(selector, cases) = match_
-      checkMatchVariablePatterns(match_)
+
+      val (nonSyntheticCases, defaultOverride) = cases match {
+        case init :+ last if treeInfo isSyntheticDefaultCase last =>
+          (init, Some(((scrut: Tree) => last.body)))
+        case _ =>
+          (cases, None)
+      }
+
+      checkMatchVariablePatterns(nonSyntheticCases)
 
       // we don't transform after uncurry
       // (that would require more sophistication when generating trees,
@@ -296,14 +301,10 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
 
       // val packedPt = repeatedToSeq(typer.packedType(match_, context.owner))
 
-      // the alternative to attaching the default case override would be to simply
-      // append the default to the list of cases and suppress the unreachable case error that may arise (once we detect that...)
-      val matchFailGenOverride = match_.attachments.get[DefaultOverrideMatchAttachment].map{case DefaultOverrideMatchAttachment(default) => ((scrut: Tree) => default)}
-
       val selectorSym = freshSym(selector.pos, pureType(selectorTp)) setFlag treeInfo.SYNTH_CASE_FLAGS
 
       // pt = Any* occurs when compiling test/files/pos/annotDepMethType.scala  with -Xexperimental
-      val combined = combineCases(selector, selectorSym, cases map translateCase(selectorSym, pt), pt, matchOwner, matchFailGenOverride)
+      val combined = combineCases(selector, selectorSym, nonSyntheticCases map translateCase(selectorSym, pt), pt, matchOwner, defaultOverride)
 
       if (Statistics.canEnable) Statistics.stopTimer(patmatNanos, start)
       combined