1 files changed, 45 insertions, 0 deletions
diff --git a/test/functional/eval/let_spec.lua b/test/functional/eval/let_spec.lua
new file mode 100644
index 0000000000..1bd3405698
--- /dev/null
+++ b/test/functional/eval/let_spec.lua
@@ -0,0 +1,45 @@
+local helpers = require('test.functional.helpers')(after_each)
+
+local eq = helpers.eq
+local clear = helpers.clear
+local meths = helpers.meths
+local redir_exec = helpers.redir_exec
+local source = helpers.source
+
+before_each(clear)
+
+describe(':let command', function()
+  it('correctly lists variables with curly-braces', function()
+    meths.set_var('v', {0})
+    eq('\nv                     [0]', redir_exec('let {"v"}'))
+  end)
+
+  it('correctly lists variables with subscript', function()
+    meths.set_var('v', {0})
+    eq('\nv[0]                  #0', redir_exec('let v[0]'))
+    eq('\ng:["v"][0]            #0', redir_exec('let g:["v"][0]'))
+    eq('\n{"g:"}["v"][0]        #0', redir_exec('let {"g:"}["v"][0]'))
+  end)
+
+  it(":unlet self-referencing node in a List graph #6070", function()
+    -- :unlet-ing a self-referencing List must not allow GC on indirectly
+    -- referenced in-scope Lists. Before #6070 this caused use-after-free.
+    source([=[
+      let [l1, l2] = [[], []]
+      echo 'l1:' . id(l1)
+      echo 'l2:' . id(l2)
+      echo ''
+      let [l3, l4] = [[], []]
+      call add(l4, l4)
+      call add(l4, l3)
+      call add(l3, 1)
+      call add(l2, l2)
+      call add(l2, l1)
+      call add(l1, 1)
+      unlet l2
+      unlet l4
+      call garbagecollect(1)
+      call feedkeys(":\e:echo l1 l3\n:echo 42\n:cq\n", "t")
+    ]=])
+  end)
+end)