fix-#9026 eliminate .. in paths

Author: bishabosha

compiler/src/dotty/tools/dotc/semanticdb/ExtractSemanticDB.scala

@@ -12,6 +12,7 @@ import Names.Name
 import StdNames.nme
 import util.Spans.Span
 import util.{SourceFile, SourcePosition}
+import scala.jdk.CollectionConverters._
 import collection.mutable
 import java.nio.file.Paths
 
@@ -594,8 +595,20 @@ object ExtractSemanticDB:
 
   def write(source: SourceFile, occurrences: List[SymbolOccurrence], symbolInfos: List[SymbolInformation])(using Context): Unit =
     def absolutePath(path: Path): Path = path.toAbsolutePath.normalize
+    def common(root: Path, i1: java.util.Iterator[Path], i2: java.util.Iterator[Path]) =
+      require(root != null)
+      var res: Path = root
+      var next: Path = null
+      while
+        i1.hasNext && i2.hasNext
+        && { next = i1.next; next } == i2.next
+      do res = res.resolve(next)
+      res
+    end common
     val sourcePath = absolutePath(source.file.jpath)
-    val sourceRoot = absolutePath(Paths.get(ctx.settings.sourceroot.value))
+    val sourceRoot =
+      val sourceRoot0 = absolutePath(Paths.get(ctx.settings.sourceroot.value))
+      common(sourcePath.getRoot, sourcePath.iterator, sourceRoot0.iterator)
     val semanticdbTarget =
       val semanticdbTargetSetting = ctx.settings.semanticdbTarget.value
       absolutePath(

compiler/test/dotty/tools/dotc/core/tasty/CommentPicklingTest.scala

@@ -82,7 +82,7 @@ class CommentPicklingTest {
     Directory.inTempDirectory { tmp =>
       val sourceFiles = sources.zipWithIndex.map {
         case (src, id) =>
-          val path = tmp./(File("Src$id.scala")).toAbsolute
+          val path = tmp./(File(s"Src$id.scala")).toAbsolute
           path.writeAll(src)
           path.toString
       }