Merge pull request #4118 from retronym/ticket/5639

SI-5639 Fix spurious discarding of implicit import

12 files changed, 184 insertions, 14 deletions

diff --git a/test/files/neg/t2866.check b/test/files/neg/t2866.check
new file mode 100644
index 0000000000..340fb8da22
--- /dev/null
+++ b/test/files/neg/t2866.check
@@ -0,0 +1,17 @@
+t2866.scala:30: warning: imported `one' is permanently hidden by definition of value one
+    import A.one // warning: imported `one' is permanently hidden by definition of value one.
+             ^
+t2866.scala:42: error: ambiguous implicit values:
+ both value two of type Int
+ and value one in object A of type => Int
+ match expected type Int
+    assert(implicitly[Int] == 2) // !!! Not ambiguous in 2.8.0. Ambigous in 2.7.6
+                     ^
+t2866.scala:50: error: ambiguous implicit values:
+ both value two of type Int
+ and value one in object A of type => Int
+ match expected type Int
+    assert(implicitly[Int] == 2) // !!! Not ambiguous in 2.8.0. Ambiguous in 2.7.6
+                     ^
+one warning found
+two errors found
diff --git a/test/files/neg/t2866.scala b/test/files/neg/t2866.scala
new file mode 100644
index 0000000000..55ebff9710
--- /dev/null
+++ b/test/files/neg/t2866.scala
@@ -0,0 +1,59 @@
+// for 2.7.x compatibility
+
+object A {
+  implicit val one = 1
+}
+
+object Test {
+
+  locally {
+    import A._
+    locally {
+      // assert(implicitly[Int] == 1) // error: could not find implicit value for parameter e: Int.
+                                     // !!! Why one A.one?
+      // (I assume you mean: why _not_ A.one? A.one is shadowed by local one.
+      // but the local one cannot be used yet because it does not have an explicit type.
+      implicit val one = 2
+      assert(implicitly[Int] == 2)
+      assert(one == 2)
+    }
+  }
+
+  locally {
+    import A._
+    implicit val one: Int = 2
+    assert(implicitly[Int] == 2)
+    assert(one == 2)
+  }
+
+  locally {
+    import A.one // warning: imported `one' is permanently hidden by definition of value one.
+                 // !!! Really?
+    //assert(implicitly[Int] == 1)
+    implicit val one = 2
+    assert(implicitly[Int] == 2) // !!! why not 2?
+    assert(one == 2)
+  }
+
+  locally {
+    import A.one
+    assert(implicitly[Int] == 1)
+    implicit val two = 2
+    assert(implicitly[Int] == 2) // !!! Not ambiguous in 2.8.0. Ambigous in 2.7.6
+  }
+
+  locally {
+    import A._
+    assert(implicitly[Int] == 1)
+    implicit val two = 2
+    import A.{one => _}
+    assert(implicitly[Int] == 2) // !!! Not ambiguous in 2.8.0. Ambiguous in 2.7.6
+  }
+
+  locally {
+    import A.{one => _, _}
+    implicit val two = 2
+    assert(implicitly[Int] == 2) // not ambiguous in 2.8.0 nor im ambiguous in 2.7.6
+  }
+
+}
diff --git a/test/files/neg/t5639b.check b/test/files/neg/t5639b.check
new file mode 100644
index 0000000000..faa1766660
--- /dev/null
+++ b/test/files/neg/t5639b.check
@@ -0,0 +1,4 @@
+A_2.scala:6: error: could not find implicit value for parameter e: Int
+  implicitly[Int]
+            ^
+one error found
diff --git a/test/files/neg/t5639b/A_1.scala b/test/files/neg/t5639b/A_1.scala
new file mode 100644
index 0000000000..c5da10eae4
--- /dev/null
+++ b/test/files/neg/t5639b/A_1.scala
@@ -0,0 +1,17 @@
+import Implicits._
+
+class Baz
+
+object Test {
+  implicitly[Int]
+}
+
+object Implicits  {
+  implicit val Baz: Int = 0
+  // This implicit was being ignored by `isQualifyingImplicit`
+  // if the classpath contained a class file for `class Baz`.
+  // This is because the package scope contains a speculative
+  // symbol for `object Baz` which is entered by `SymbolLoaders`
+  // before looking inside the class file. (A Java originated
+  // classfile results in the class/module symbol pair.)
+}
diff --git a/test/files/neg/t5639b/A_2.scala b/test/files/neg/t5639b/A_2.scala
new file mode 100644
index 0000000000..2bb36273e0
--- /dev/null
+++ b/test/files/neg/t5639b/A_2.scala
@@ -0,0 +1,11 @@
+import Implicits._
+
+class Baz
+
+object Test {
+  implicitly[Int]
+}
+
+object Implicits  {
+  implicit val Baz: Int = 0
+}
diff --git a/test/files/pos/t5639.flags b/test/files/pos/t5639.flags
new file mode 100644
index 0000000000..0acce1e7ce
--- /dev/null
+++ b/test/files/pos/t5639.flags
@@ -0,0 +1 @@
+-Xsource:2.12
diff --git a/test/files/pos/t5639/A_1.scala b/test/files/pos/t5639/A_1.scala
new file mode 100644
index 0000000000..c5da10eae4
--- /dev/null
+++ b/test/files/pos/t5639/A_1.scala
@@ -0,0 +1,17 @@
+import Implicits._
+
+class Baz
+
+object Test {
+  implicitly[Int]
+}
+
+object Implicits  {
+  implicit val Baz: Int = 0
+  // This implicit was being ignored by `isQualifyingImplicit`
+  // if the classpath contained a class file for `class Baz`.
+  // This is because the package scope contains a speculative
+  // symbol for `object Baz` which is entered by `SymbolLoaders`
+  // before looking inside the class file. (A Java originated
+  // classfile results in the class/module symbol pair.)
+}
diff --git a/test/files/pos/t5639/A_2.scala b/test/files/pos/t5639/A_2.scala
new file mode 100644
index 0000000000..2bb36273e0
--- /dev/null
+++ b/test/files/pos/t5639/A_2.scala
@@ -0,0 +1,11 @@
+import Implicits._
+
+class Baz
+
+object Test {
+  implicitly[Int]
+}
+
+object Implicits  {
+  implicit val Baz: Int = 0
+}
diff --git a/test/files/pos/t5639/Bar.scala b/test/files/pos/t5639/Bar.scala
deleted file mode 100644
index f577500acd..0000000000
--- a/test/files/pos/t5639/Bar.scala
+++ /dev/null
@@ -1,7 +0,0 @@
-package pack.age
-
-import pack.age.Implicits._
-
-object Quux {
-  def baz : Baz   = 1
-}
diff --git a/test/files/pos/t5639/Foo.scala b/test/files/pos/t5639/Foo.scala
deleted file mode 100644
index 1a07734a8e..0000000000
--- a/test/files/pos/t5639/Foo.scala
+++ /dev/null
@@ -1,7 +0,0 @@
-package pack.age
-
-class Baz
-
-object Implicits  {
-  implicit def Baz(n: Int): Baz = new Baz
-}
diff --git a/test/files/run/t2866.check b/test/files/run/t2866.check
new file mode 100644
index 0000000000..7f52da85fb
--- /dev/null
+++ b/test/files/run/t2866.check
@@ -0,0 +1,3 @@
+t2866.scala:30: warning: imported `one' is permanently hidden by definition of value one
+    import A.one // warning: imported `one' is permanently hidden by definition of value one.
+             ^
diff --git a/test/files/run/t2866.scala b/test/files/run/t2866.scala
new file mode 100644
index 0000000000..8059107583
--- /dev/null
+++ b/test/files/run/t2866.scala
@@ -0,0 +1,44 @@
+// for 2.7.x compatibility
+
+object A {
+  implicit val one = 1
+}
+
+object Test extends App {
+
+  locally {
+    import A._
+    locally {
+      // assert(implicitly[Int] == 1) // error: could not find implicit value for parameter e: Int.
+                                     // !!! Why one A.one?
+      // (I assume you mean: why _not_ A.one? A.one is shadowed by local one.
+      // but the local one cannot be used yet because it does not have an explicit type.
+      implicit val one = 2
+      assert(implicitly[Int] == 2)
+      assert(one == 2)
+    }
+  }
+
+  locally {
+    import A._
+    implicit val one: Int = 2
+    assert(implicitly[Int] == 2)
+    assert(one == 2)
+  }
+
+  locally {
+    import A.one // warning: imported `one' is permanently hidden by definition of value one.
+                 // !!! Really?
+    //assert(implicitly[Int] == 1)
+    implicit val one = 2
+    assert(implicitly[Int] == 2) // !!! why not 2?
+    assert(one == 2)
+  }
+
+  locally {
+    import A.{one => _, _}
+    implicit val two = 2
+    assert(implicitly[Int] == 2) // not ambiguous in 2.8.0 nor im ambiguous in 2.7.6
+  }
+
+}