backport: Finer grained accessibility check for auto-imports

Author: tgodzik

presentation-compiler/src/main/dotty/tools/pc/CompilerSearchVisitor.scala

@@ -28,7 +28,7 @@ class CompilerSearchVisitor(
     owner.isStatic && owner.isPublic
 
   private def isAccessible(sym: Symbol): Boolean = try
-    sym != NoSymbol && sym.isPublic && sym.isStatic || isAccessibleImplicitClass(sym)
+    (sym != NoSymbol && sym.isAccessibleFrom(ctx.owner.info) && sym.isStatic) || isAccessibleImplicitClass(sym)
   catch
     case err: AssertionError =>
       logger.log(Level.WARNING, err.getMessage())

presentation-compiler/src/main/dotty/tools/pc/PcDefinitionProvider.scala

@@ -137,7 +137,7 @@ class PcDefinitionProvider(
                     SemanticdbSymbols.symbolName(sym),
                     List(loc).asJava,
                   )
-                else DefinitionResultImpl.empty
+              else DefinitionResultImpl.empty
             case None =>
               DefinitionResultImpl.empty
         else

presentation-compiler/test/dotty/tools/pc/tests/completion/CompletionSnippetSuite.scala

@@ -385,6 +385,29 @@ class CompletionSnippetSuite extends BaseCompletionSuite:
     )
 
   @Test def `no-apply` =
+    checkSnippet(
+      s"""|package example
+          |
+          |object Widget{}
+          |object Main {
+          |  Wi@@
+          |}
+          |""".stripMargin,
+      """|Widget -  example
+         |Window -  java.awt
+         |WindowPeer -  java.awt.peer
+         |WithFilter - [A](p: A => Boolean, xs: Array[A]): WithFilter[A]
+         |WithFilter - [A, CC[_$$2]](self: IterableOps[A, CC, ?], p: A => Boolean): WithFilter[A, CC]
+         |WithFilter - [K, V, IterableCC[_$$3], CC[_$$4,_$$5] <: IterableOps[?, AnyConstr, ?]](self: MapOps[K, V, CC, ?] & IterableOps[(K, V), IterableCC, ?], p: ((K, V)) => Boolean): WithFilter[K, V, IterableCC, CC]
+         |WithFilter - [K, V, IterableCC[_$$1], MapCC[X,Y] <: scala.collection.Map[X, Y], CC[X,Y] <: scala.collection.Map[X, Y] & SortedMapOps[X, Y, CC, ?]](self: SortedMapOps[K, V, CC, ?] & MapOps[K, V, MapCC, ?] & IterableOps[(K, V), IterableCC, ?], p: ((K, V)) => Boolean): WithFilter[K, V, IterableCC, MapCC, CC]
+         |WithFilter - [A, IterableCC[_$$1], CC[X] <: SortedSet[X]](self: SortedSetOps[A, CC, ?] & IterableOps[A, IterableCC, ?], p: A => Boolean): WithFilter[A, IterableCC, CC]
+         |WithFilter - (p: Char => Boolean, s: String): WithFilter
+         |WithFilter - [A](l: Stream[A] @uncheckedVariance, p: A => Boolean): WithFilter[A]
+         |""".stripMargin,
+      includeDetail = true,
+    )
+
+  @Test def `no-apply2` =
     checkSnippet(
       s"""|package example
           |

presentation-compiler/test/dotty/tools/pc/tests/completion/CompletionSuite.scala

@@ -2107,6 +2107,19 @@ class CompletionSuite extends BaseCompletionSuite:
         |""".stripMargin
    )
 
+  @Test def `shadowing` =
+   check(
+     """|package pkg
+        |object Main {
+        |  val x = ListBuff@@
+        |}
+        |""".stripMargin,
+     """|ListBuffer[A](elems: A*): ListBuffer[A] - scala.collection.mutable
+        |new ListBuffer[A]: ListBuffer[A] - scala.collection.mutable
+        |ListBuffer - scala.collection.mutable
+        |""".stripMargin
+   )
+
   @Test def `conflict-edit-2` =
     checkEdit(
       """|package a