eval: Add id() function and make printf("%p") return something useful (#6095)

1 files changed, 32 insertions, 0 deletions

diff --git a/test/functional/eval/printf_spec.lua b/test/functional/eval/printf_spec.lua
index c84290ceef..27e24c4118 100644
--- a/test/functional/eval/printf_spec.lua
+++ b/test/functional/eval/printf_spec.lua
@@ -1,7 +1,10 @@
 local helpers = require('test.functional.helpers')(after_each)
+
 local clear = helpers.clear
 local eq = helpers.eq
+local eval = helpers.eval
 local funcs = helpers.funcs
+local meths = helpers.meths
 local exc_exec = helpers.exc_exec
 
 describe('printf()', function()
@@ -57,4 +60,33 @@ describe('printf()', function()
   it('errors out when %b modifier is used for a float', function()
     eq('Vim(call):E805: Using a Float as a Number', exc_exec('call printf("%b", 3.1415926535)'))
   end)
+  it('works with %p correctly', function()
+    local null_ret = nil
+    local seen_rets = {}
+    -- Collect all args in an array to avoid possible allocation of the same
+    -- address after freeing unreferenced values.
+    meths.set_var('__args', {})
+    local function check_printf(expr, is_null)
+      eq(0, exc_exec('call add(__args, ' .. expr .. ')'))
+      eq(0, exc_exec('let __result = printf("%p", __args[-1])'))
+      local id_ret = eval('id(__args[-1])')
+      eq(id_ret, meths.get_var('__result'))
+      if is_null then
+        if null_ret then
+          eq(null_ret, id_ret)
+        else
+          null_ret = id_ret
+        end
+      else
+        eq(nil, seen_rets[id_ret])
+        seen_rets[id_ret] = expr
+      end
+      meths.del_var('__result')
+    end
+    check_printf('v:_null_list', true)
+    check_printf('v:_null_dict', true)
+    check_printf('[]')
+    check_printf('{}')
+    check_printf('function("tr", ["a"])')
+  end)
 end)