Merge pull request #6465 from dotty-staging/fix-#6435

Fix #6435: Collect variables in quoted patterns

Author: nicolasstucki

compiler/src/dotty/tools/dotc/ast/Desugar.scala

@@ -1550,6 +1550,14 @@ object desugar {
         trees foreach collect
       case Block(Nil, expr) =>
         collect(expr)
+      case Quote(expr) =>
+        new TreeTraverser {
+          def traverse(tree: untpd.Tree)(implicit ctx: Context): Unit = tree match {
+            case Splice(expr) => collect(expr)
+            case TypSplice(expr) => collect(expr)
+            case _ => traverseChildren(tree)
+          }
+        }.traverse(expr)
       case _ =>
     }
     collect(tree)

tests/pos/i6435.scala

@@ -0,0 +1,12 @@
+class Foo {
+  import scala.quoted._
+  import scala.quoted.matching._
+  def f(sc: quoted.Expr[StringContext]) given tasty.Reflection: Unit = {
+
+    val '{ StringContext(${parts}: _*) } = sc
+    val ps0: Expr[Seq[String]] = parts
+
+    val '{ StringContext(${ExprSeq(parts2)}: _*) } = sc
+    val ps: Seq[Expr[String]] = parts2
+  }
+}