vim-patch:8.1.0613: when executing an insecure function the secure flag is stuck

Problem:    When executing an insecure function the secure flag is stuck.
            (Gabriel Barta)
Solution:   Restore "secure" instead of decrementing it. (closes vim/vim#3705)
https://github.com/vim/vim/commit/48f377a476e4a3312aa0e3535aba170484b59483

3 files changed, 33 insertions, 12 deletions

diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index c8ed7d0b37..d12ba14911 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -5112,6 +5112,7 @@ chk_modeline(
     *e = NUL;                         // truncate the set command
 
     if (*s != NUL) {                  // skip over an empty "::"
+      const int secure_save = secure;
       save_SID = current_SID;
       current_SID = SID_MODELINE;
       // Make sure no risky things are executed as a side effect.
@@ -5119,7 +5120,7 @@ chk_modeline(
 
       retval = do_set(s, OPT_MODELINE | OPT_LOCAL | flags);
 
-      secure--;
+      secure = secure_save;
       current_SID = save_SID;
       if (retval == FAIL) {                   // stop if error found
         break;
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 41d3b03e41..b93f98f6c5 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -1833,7 +1833,7 @@ int do_set(
 
             {
               uint32_t *p = insecure_flag(opt_idx, opt_flags);
-              int did_inc_secure = false;
+              const int secure_saved = secure;
 
               // When an option is set in the sandbox, from a
               // modeline or in secure mode, then deal with side
@@ -1844,23 +1844,20 @@ int do_set(
                   || sandbox != 0
                   || (opt_flags & OPT_MODELINE)
                   || (!value_is_replaced && (*p & P_INSECURE))) {
-                  did_inc_secure = true;
-                  secure++;
+                secure++;
               }
 
-              // Handle side effects, and set the global value for
-              // ":set" on local options. Note: when setting 'syntax'
-              // or 'filetype' autocommands may be triggered that can
-              // cause havoc.
+              // Handle side effects, and set the global value
+              // for ":set" on local options. Note: when setting
+              // 'syntax' or 'filetype' autocommands may be
+              // triggered that can cause havoc.
               errmsg = did_set_string_option(opt_idx, (char_u **)varp,
                                              new_value_alloced, oldval,
                                              errbuf, sizeof(errbuf),
                                              opt_flags, &value_checked);
 
-              if (did_inc_secure) {
-                secure--;
-              }
-          }
+              secure = secure_saved;
+            }
 
             if (errmsg == NULL) {
               if (!starting) {
diff --git a/src/nvim/testdir/test_autocmd.vim b/src/nvim/testdir/test_autocmd.vim
index cf08df4b08..d13761e2ba 100644
--- a/src/nvim/testdir/test_autocmd.vim
+++ b/src/nvim/testdir/test_autocmd.vim
@@ -677,6 +677,29 @@ func Test_OptionSet_diffmode_close()
   "delfunc! AutoCommandOptionSet
 endfunc
 
+func Test_OptionSet_modeline()
+  throw 'skipped: Nvim does not support test_override()'
+  call test_override('starting', 1)
+  au! OptionSet
+  augroup set_tabstop
+    au OptionSet tabstop call timer_start(1, {-> execute("echo 'Handler called'", "")})
+  augroup END
+  call writefile(['vim: set ts=7 sw=5 :', 'something'], 'XoptionsetModeline')
+  set modeline
+  let v:errmsg = ''
+  call assert_fails('split XoptionsetModeline', 'E12:')
+  call assert_equal(7, &ts)
+  call assert_equal('', v:errmsg)
+
+  augroup set_tabstop
+    au!
+  augroup END
+  bwipe!
+  set ts&
+  call delete('XoptionsetModeline')
+  call test_override('starting', 0)
+endfunc
+
 " Test for Bufleave autocommand that deletes the buffer we are about to edit.
 func Test_BufleaveWithDelete()
   new | edit Xfile1