Fix completion after application with implicit arguments

`List(1, 2, 3).map(f).<ctrl-space>` now works; before
the tree had the type `(bf: CanBuildFrom[...]):...` and
did not contribute completions from the result type.

This commit checks if the tree has an implicit method
type, and typechecks it as a qualifier. That is enough
to get to `adaptToImplicitMethod` in the type checker,
infer the implicit arguments, and compute the final result
type accordingly.

1 files changed, 7 insertions, 2 deletions

diff --git a/src/compiler/scala/tools/nsc/interactive/Global.scala b/src/compiler/scala/tools/nsc/interactive/Global.scala
index 84670750d7..49f6cb2373 100644
--- a/src/compiler/scala/tools/nsc/interactive/Global.scala
+++ b/src/compiler/scala/tools/nsc/interactive/Global.scala
@@ -999,7 +999,13 @@ class Global(settings: Settings, _reporter: Reporter, projectName: String = "")
 
     val context = doLocateContext(pos)
 
-    if (tree.tpe == null)
+    val shouldTypeQualifier = tree.tpe match {
+      case null           => true
+      case mt: MethodType => mt.isImplicit
+      case _              => false
+    }
+
+    if (shouldTypeQualifier)
       // TODO: guard with try/catch to deal with ill-typed qualifiers.
       tree = analyzer.newTyper(context).typedQualifier(tree)
 
@@ -1192,4 +1198,3 @@ class Global(settings: Settings, _reporter: Reporter, projectName: String = "")
 }
 
 object CancelException extends Exception
-