vim-patch:8.2.3609: internal error when ModeChanged is triggered recursively

Problem:    Internal error when ModeChanged is triggered when v:event is
            already in use.
Solution:   Save and restore v:event if needed.
https://github.com/vim/vim/commit/3075a45592fe76f2febb6321632a23e352efe949

In the vim codebase there is no occurrence of get_vim_var_dict(VV_EVENT)
after the above patch, so in order to hold the same invariant in the
neovim codebase we needed to replace more occurrences than the related
vim patch.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/nvim/aucmd.c b/src/nvim/aucmd.c
index af519dcba9..a236b47027 100644
--- a/src/nvim/aucmd.c
+++ b/src/nvim/aucmd.c
@@ -8,6 +8,7 @@
 #include "nvim/ex_getln.h"
 #include "nvim/fileio.h"
 #include "nvim/main.h"
+#include "nvim/misc1.h"
 #include "nvim/os/os.h"
 #include "nvim/ui.h"
 #include "nvim/vim.h"
@@ -25,13 +26,14 @@ void do_autocmd_uienter(uint64_t chanid, bool attached)
   }
   recursive = true;
 
-  dict_T *dict = get_vim_var_dict(VV_EVENT);
+  save_v_event_T save_v_event;
+  dict_T *dict = get_v_event(&save_v_event);
   assert(chanid < VARNUMBER_MAX);
   tv_dict_add_nr(dict, S_LEN("chan"), (varnumber_T)chanid);
   tv_dict_set_keys_readonly(dict);
   apply_autocmds(attached ? EVENT_UIENTER : EVENT_UILEAVE,
                  NULL, NULL, false, curbuf);
-  tv_dict_clear(dict);
+  restore_v_event(dict, &save_v_event);
 
   recursive = false;
 }