fix(messages)!: vim.ui_attach message callbacks are unsafe

Problem:  Lua callbacks for "msg_show" events with vim.ui_attach() are
          executed when it is not safe.
Solution: Disallow non-fast API calls for "msg_show" event callbacks.
          Automatically detach callback after excessive errors.
          Make sure fast APIs do not modify Nvim state.

1 files changed, 0 insertions, 68 deletions

diff --git a/test/functional/vimscript/eval_spec.lua b/test/functional/vimscript/eval_spec.lua
index de1a3d7c73..2a4835f7e1 100644
--- a/test/functional/vimscript/eval_spec.lua
+++ b/test/functional/vimscript/eval_spec.lua
@@ -25,8 +25,6 @@ local command = n.command
 local write_file = t.write_file
 local api = n.api
 local sleep = vim.uv.sleep
-local matches = t.matches
-local pcall_err = t.pcall_err
 local assert_alive = n.assert_alive
 local poke_eventloop = n.poke_eventloop
 local feed = n.feed
@@ -227,72 +225,6 @@ describe('listing functions using :function', function()
       exec_capture(('function <lambda>%s'):format(num))
     )
   end)
-
-  it('does not crash if another function is deleted while listing', function()
-    local _ = Screen.new(80, 24)
-    matches(
-      'Vim%(function%):E454: Function list was modified$',
-      pcall_err(
-        exec_lua,
-        [=[
-      vim.cmd([[
-        func Func1()
-        endfunc
-        func Func2()
-        endfunc
-        func Func3()
-        endfunc
-      ]])
-
-      local ns = vim.api.nvim_create_namespace('test')
-
-      vim.ui_attach(ns, { ext_messages = true }, function(event, _, content)
-        if event == 'msg_show' and content[1][2] == 'function Func1()'  then
-          vim.cmd('delfunc Func3')
-        end
-      end)
-
-      vim.cmd('function')
-
-      vim.ui_detach(ns)
-    ]=]
-      )
-    )
-    assert_alive()
-  end)
-
-  it('does not crash if the same function is deleted while listing', function()
-    local _ = Screen.new(80, 24)
-    matches(
-      'Vim%(function%):E454: Function list was modified$',
-      pcall_err(
-        exec_lua,
-        [=[
-      vim.cmd([[
-        func Func1()
-        endfunc
-        func Func2()
-        endfunc
-        func Func3()
-        endfunc
-      ]])
-
-      local ns = vim.api.nvim_create_namespace('test')
-
-      vim.ui_attach(ns, { ext_messages = true }, function(event, _, content)
-        if event == 'msg_show' and content[1][2] == 'function Func1()'  then
-          vim.cmd('delfunc Func2')
-        end
-      end)
-
-      vim.cmd('function')
-
-      vim.ui_detach(ns)
-    ]=]
-      )
-    )
-    assert_alive()
-  end)
 end)
 
 it('no double-free in garbage collection #16287', function()