patch 8.0.0092
Problem:    C indenting does not support nested namespaces that C++ 17 has.
Solution:   Add check that passes double colon inside a name. (Pauli, closes
            #1214)
diff --git a/src/testdir/test3.ok b/src/testdir/test3.ok
index c4c01a3..2f9572c 100644
--- a/src/testdir/test3.ok
+++ b/src/testdir/test3.ok
@@ -1730,6 +1730,26 @@
 {
 111111111111111111;
 }
+namespace test::cpp17
+{
+111111111111111111;
+}
+namespace ::incorrectcpp17
+{
+	111111111111111111;
+}
+namespace test::incorrectcpp17::
+{
+	111111111111111111;
+}
+namespace test:incorrectcpp17
+{
+	111111111111111111;
+}
+namespace test:::incorrectcpp17
+{
+	111111111111111111;
+}
 namespace{
 111111111111111111;
 }