Fix inputTaskDyn not working

This fixes the following error when trying to use inputTaskDyn in a build:

[error] /tmp/sbt_8316130f/input-task-dyn/build.sbt:11: error: Macro
expansion contains free type variable T defined by wrap in
InputConvert.scala:76:20. Have you forgotten to use c.WeakTypeTag
annotation for this type parameter? If you
have troubles tracking free type variables, consider using -Xlog-free-types (out-1)
[error]     runFoo := Def.inputTaskDyn { (out-1)
[error]                                ^ (out-1)
[info] [error] sbt.compiler.EvalException: Type error in expression (out-3) (out-1)

I have no idea what the error means, I just implemented the suggested fix.

main-settings/src/main/scala/sbt/std/InputConvert.scala

@@ -73,7 +73,7 @@ object InitParserConvert extends Convert {
       case _                        => Converted.NotApplicable[c.type]
     }
 
-  private def wrap[T](c: blackbox.Context)(tree: c.Tree): Converted[c.type] = {
+  private def wrap[T: c.WeakTypeTag](c: blackbox.Context)(tree: c.Tree): Converted[c.type] = {
     val e = c.Expr[State => Parser[T]](tree)
     val t = c.universe.reify { Def.valueStrict[State => Parser[T]](e.splice) }
     Converted.Success[c.type](t.tree)

sbt/src/sbt-test/actions/input-task-dyn/Bar.scala

@@ -0,0 +1,5 @@
+object Bar {
+  def main(args: Array[String]): Unit = {
+    println("Bar: " + args.toList.toString)
+  }
+}

sbt/src/sbt-test/actions/input-task-dyn/Foo.scala

@@ -0,0 +1,5 @@
+object Foo {
+  def main(args: Array[String]): Unit = {
+    println("Foo: " + args.toList.toString)
+  }
+}

sbt/src/sbt-test/actions/input-task-dyn/build.sbt

@@ -0,0 +1,18 @@
+import complete.Parser
+
+// http://www.scala-sbt.org/0.13/docs/Input-Tasks.html
+
+val runFoo = inputKey[Unit]("Runs Foo with passed arguments")
+val check = taskKey[Unit]("")
+
+lazy val root = (project in file(".")).
+  settings(
+    name := "run-test",
+    runFoo := Def.inputTaskDyn {
+        val args = Def.spaceDelimited().parsed
+        (runMain in Compile).toTask(s" Foo " + args.mkString(" "))
+    }.evaluated,
+    check := {
+      val x = runFoo.toTask(" hi ho").value
+    }
+  )

sbt/src/sbt-test/actions/input-task-dyn/test

@@ -0,0 +1 @@
+> check