Merge pull request #5963 from dotty-staging/fix/gotodef-exception

IDE: Avoid exception when doing go-to-definition on something that doesn't exist

Author: smarter

compiler/src/dotty/tools/dotc/transform/SymUtils.scala

@@ -150,8 +150,9 @@ class SymUtils(val self: Symbol) extends AnyVal {
 
   /** Is symbol directly or indirectly owned by a term symbol? */
   @tailrec final def isLocal(implicit ctx: Context): Boolean = {
-    val owner = self.owner
-    if (owner.isTerm) true
+    val owner = self.maybeOwner
+    if (!owner.exists) false
+    else if (owner.isTerm) true
     else if (owner.is(Package)) false
     else owner.isLocal
   }

language-server/test/dotty/tools/languageserver/DefinitionTest.scala

@@ -367,4 +367,15 @@ class DefinitionTest {
       .definition(m17 to m18, List(m11 to m12))
       .definition(m19 to m20, List(m13 to m14))
   }
+
+  @Test def definitionDoesNotExist: Unit = withSources(
+    code"""object Foo {
+          |  ${m1}unknown1${m2}
+          |  ${m3}unknown2${m4}.${m5}unknown3${m6}
+          |  Foo.${m7}unknown4${m8}
+          |}""")
+    .definition(m1 to m2, Nil)
+    .definition(m3 to m4, Nil)
+    .definition(m5 to m6, Nil)
+    .definition(m7 to m8, Nil)
 }