Merge pull request scala#3955 from som-snytt/issue/8410

SI-8410 Don't warn fatally on disabled flag

Author: gkossakowski

src/compiler/scala/tools/nsc/Reporting.scala

@@ -33,7 +33,7 @@ trait Reporting extends scala.reflect.internal.Reporting { self: ast.Positions w
         if (option) reporter.warning(pos, msg)
         else if (!(warnings contains pos)) warnings += ((pos, msg))
       def summarize() =
-        if (warnings.nonEmpty && (option.isDefault || settings.fatalWarnings)) {
+        if (warnings.nonEmpty && (option.isDefault || option)) {
           val numWarnings  = warnings.size
           val warningVerb  = if (numWarnings == 1) "was" else "were"
           val warningCount = countElementsAsString(numWarnings, s"$what warning")
@@ -105,4 +105,4 @@ trait Reporting extends scala.reflect.internal.Reporting { self: ast.Positions w
         reporter.error(NoPosition, "No warnings can be incurred under -Xfatal-warnings.")
     }
   }
-}
+}

test/files/pos/t8410.flags

@@ -0,0 +1 @@
+-optimise -Xfatal-warnings -deprecation:false -Yinline-warnings:false

test/files/pos/t8410.scala

@@ -0,0 +1,15 @@
+
+object Test extends App {
+  @deprecated("","") def f = 42
+  @deprecated("","") def z = f
+  def g = { @deprecated("","") def _f = f ; _f }                   // warns in 2.11.0-M8
+  def x = { @deprecated("","") class X { def x = f } ; new X().x } // warns in 2.11.0-M8
+  Console println g
+  Console println f  // warns
+
+  @deprecated("","") trait T
+  object T extends T { def t = f }
+  Console println T.t
+
+  def k = List(0).dropWhile(_ < 1)   // inlining warns doubly
+}