3 files changed, 84 insertions, 1 deletions
diff --git a/tests/concepts/treversable.nim b/tests/concepts/treversable.nim
new file mode 100644
index 000000000..6ebc077d9
--- /dev/null
+++ b/tests/concepts/treversable.nim
@@ -0,0 +1,31 @@
+# issue 7705, 7703, 7702
+discard """
+  output: '''
+z
+e
+  '''
+"""
+
+type
+  Reversable*[T] = concept a
+    a[int] is T
+    a.high is int
+    a.len is int
+    a.low is int
+
+proc get[T](s: Reversable[T], n: int): T =
+  s[n]
+
+proc hi[T](s: Reversable[T]): int =
+  s.high
+
+proc lo[T](s: Reversable[T]): int =
+  s.low
+
+iterator reverse*[T](s: Reversable[T]): T =
+  assert hi(s) - lo(s) == len(s) - 1
+  for z in hi(s).countdown(lo(s)):
+    yield s.get(z)
+
+for s in @["e", "z"].reverse:
+  echo s
diff --git a/tests/vm/tnilref.nim b/tests/vm/tnilref.nim
new file mode 100644
index 000000000..5e27cf0cb
--- /dev/null
+++ b/tests/vm/tnilref.nim
@@ -0,0 +1,7 @@
+discard """
+  errormsg: "attempt to access a nil address"
+"""
+
+static:
+    var s: ref int
+    s[] = 1
\ No newline at end of file
diff --git a/tests/vm/tref.nim b/tests/vm/tref.nim
index 517a67fb0..27b7bf313 100644
--- a/tests/vm/tref.nim
+++ b/tests/vm/tref.nim
@@ -9,4 +9,49 @@ static:
 
   b[5] = 'c'
   doAssert a[] == "Hellocworld"
-  doAssert b[] == "Hellocworld"
\ No newline at end of file
+  doAssert b[] == "Hellocworld"
+
+  proc notGlobal() =
+    var
+      a: ref string
+      b: ref string
+    new a
+
+    a[] = "Hello world"
+    b = a
+
+    b[5] = 'c'
+    doAssert a[] == "Hellocworld"
+    doAssert b[] == "Hellocworld"
+  notGlobal()
+
+static: # bug 6081
+  block:
+    type Obj = object
+      field: ref int
+    var i: ref int
+    new(i)
+    var r = Obj(field: i)
+    var rr = r
+    r.field = nil
+    doAssert rr.field != nil
+
+  proc foo() = # Proc to avoid special global logic
+    var s: seq[ref int]
+    var i: ref int
+    new(i)
+    s.add(i)
+    var head = s[0]
+    s[0] = nil
+    doAssert head != nil
+
+  foo()
+
+static:
+
+  block: # global alias
+    var s: ref int
+    new(s)
+    var ss = s
+    s[] = 1
+    doAssert ss[] == 1
\ No newline at end of file