diff options
-rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Implicits.scala | 6 | ||||
-rw-r--r-- | test/files/pos/t7944.scala | 24 |
2 files changed, 29 insertions, 1 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala index 987a3d2202..1e89e79cdd 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala @@ -78,7 +78,11 @@ trait Implicits { }) debuglog("update buffer: " + implicitSearchContext.reportBuffer.errors) } - context.undetparams = context.undetparams filterNot result.subst.from.contains + // SI-7944 undetermined type parameters that result from inference within typedImplicit land in + // `implicitSearchContext.undetparams`, *not* in `context.undetparams` + // Here, we copy them up to parent context (analogously to the way the errors are copied above), + // and then filter out any which *were* inferred and are part of the substitutor in the implicit search result. + context.undetparams = ((context.undetparams ++ implicitSearchContext.undetparams) filterNot result.subst.from.contains).distinct if (Statistics.canEnable) Statistics.stopTimer(implicitNanos, start) if (Statistics.canEnable) Statistics.stopCounter(rawTypeImpl, rawTypeStart) diff --git a/test/files/pos/t7944.scala b/test/files/pos/t7944.scala new file mode 100644 index 0000000000..2fe2c5866d --- /dev/null +++ b/test/files/pos/t7944.scala @@ -0,0 +1,24 @@ +class M[+A, +B] + +object Test { + implicit class EitherOps[A, B](self: Either[A, B]) { + def disjunction: M[A, B] = null + } + + def foo = { + val l: Either[Int, Nothing] = Left[Int, Nothing](1) + + var ok = EitherOps(l).disjunction + + val runawayTypeVar = l.disjunction + + // reported bug: + // found : M[Int,B]; required: M[Int,Nothing] + val assign: M[Int, Nothing] = runawayTypeVar + + // variations on the theme, all failed before similarly. + val assign1: M[Int, Nothing] = {val temp = runawayTypeVar; temp} + val assign2: M[Int, String] = runawayTypeVar + val assign3: M[Int, Nothing] = {val temp = Left(1).disjunction; temp} + } +} |