Fix for SI-6706, Symbol breakage under GC.

Ensure the map key and the String in the Symbol are the
same reference by removing the old key before updating the
map with the new key -> symbol relation.

1 files changed, 14 insertions, 0 deletions

diff --git a/test/files/run/t6706.scala b/test/files/run/t6706.scala
new file mode 100644
index 0000000000..905494ca8d
--- /dev/null
+++ b/test/files/run/t6706.scala
@@ -0,0 +1,14 @@
+object Test {
+  var name = "foo" + 1
+  var s1 = Symbol(name)
+  s1 = null
+  System.gc
+  val s2 = Symbol("foo1")
+  name = null
+  System.gc
+  val s3 = Symbol("foo1")
+
+  def main(args: Array[String]): Unit = {
+    assert(s2 eq s3, ((s2, System.identityHashCode(s2), s3, System.identityHashCode(s3))))
+  }
+}