vim-patch:8.2.2426: allowing 'completefunc' to switch windows causes trouble

Problem:    Allowing 'completefunc' to switch windows causes trouble.
Solution:   use "textwinlock" instead of "textlock".
https://github.com/vim/vim/commit/28976e2accf11591c60e8a658a9e03544f0408b2

Assert E565 instead of E578.

vim-patch:8.2.0670: cannot change window when evaluating 'completefunc'

Problem:    Cannot change window when evaluating 'completefunc'.
Solution:   Make a difference between not changing text or buffers and also
            not changing window.
https://github.com/vim/vim/commit/6adb9ea0a6ca01414f4b591f379b0f829a8273c0

vim-patch:8.2.5029: "textlock" is always zero

Problem:    "textlock" is always zero.
Solution:   Remove "textlock" and rename "textwinlock" to "textlock".
            (closes vim/vim#10489)
https://github.com/vim/vim/commit/cfe456543e840d133399551f8626d985e1fb1958

6 files changed, 16 insertions, 29 deletions

diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index 2abe9068eb..c6773b3395 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -3961,7 +3961,9 @@ static void expand_by_function(int type, char_u *base)
   pos = curwin->w_cursor;
   curwin_save = curwin;
   curbuf_save = curbuf;
-  // Lock the text to avoid weird things from happening.
+  // Lock the text to avoid weird things from happening.  Also disallow
+  // switching to another window, it should not be needed and may end up in
+  // Insert mode in another buffer.
   textlock++;
 
   // Call a function, which returns a list or dict.
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index f231146d7c..80586caf8e 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -1062,11 +1062,6 @@ static void f_complete(typval_T *argvars, typval_T *rettv, FunPtr fptr)
     return;
   }
 
-  const int save_textlock = textlock;
-  // "textlock" is set when evaluating 'completefunc' but we can change text
-  // here.
-  textlock = 0;
-
   // Check for undo allowed here, because if something was already inserted
   // the line was already saved for undo and this check isn't done.
   if (!undo_allowed(curbuf)) {
@@ -1081,7 +1076,6 @@ static void f_complete(typval_T *argvars, typval_T *rettv, FunPtr fptr)
       set_completion(startcol - 1, argvars[1].vval.v_list);
     }
   }
-  textlock = save_textlock;
 }
 
 /// "complete_add()" function
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index 92c9d83045..4c26cfe500 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -2696,14 +2696,12 @@ char_u *get_cmdprompt(void)
   return ccline.cmdprompt;
 }
 
-/*
- * Return TRUE when the text must not be changed and we can't switch to
- * another window or buffer.  Used when editing the command line etc.
- */
-int text_locked(void)
+/// Return true when the text must not be changed and we can't switch to
+/// another window or buffer.  True when editing the command line etc.
+bool text_locked(void)
 {
   if (cmdwin_type != 0) {
-    return TRUE;
+    return true;
   }
   return textlock != 0;
 }
diff --git a/src/nvim/testdir/test_ins_complete.vim b/src/nvim/testdir/test_ins_complete.vim
index 532685b9de..563d8812f7 100644
--- a/src/nvim/testdir/test_ins_complete.vim
+++ b/src/nvim/testdir/test_ins_complete.vim
@@ -628,31 +628,24 @@ func Test_completefunc_error()
   call setline(1, ['', 'abcd', ''])
   call assert_fails('exe "normal 2G$a\<C-X>\<C-U>"', 'E565:')
 
-  set completefunc&
-  delfunc CompleteFunc
-  delfunc CompleteFunc2
-  close!
-endfunc
-
-func Test_completefunc_error_not_asan()
-  " The following test causes an ASAN failure.
-  CheckNotAsan
-
   " Jump to a different window from the complete function
-  func! CompleteFunc(findstart, base)
+  func CompleteFunc3(findstart, base)
     if a:findstart == 1
       return col('.') - 1
     endif
     wincmd p
     return ['a', 'b']
   endfunc
-  set completefunc=CompleteFunc
+  set completefunc=CompleteFunc3
   new
-  call assert_fails('exe "normal a\<C-X>\<C-U>"', 'E839:')
+  call assert_fails('exe "normal a\<C-X>\<C-U>"', 'E565:')
   close!
 
   set completefunc&
   delfunc CompleteFunc
+  delfunc CompleteFunc2
+  delfunc CompleteFunc3
+  close!
 endfunc
 
 " Test for returning non-string values from 'completefunc'
diff --git a/src/nvim/testdir/test_popup.vim b/src/nvim/testdir/test_popup.vim
index 7afa31a6d1..aef32fc504 100644
--- a/src/nvim/testdir/test_popup.vim
+++ b/src/nvim/testdir/test_popup.vim
@@ -655,8 +655,8 @@ func Test_complete_func_mess()
   set completefunc=MessComplete
   new
   call setline(1, 'Ju')
-  call feedkeys("A\<c-x>\<c-u>/\<esc>", 'tx')
-  call assert_equal('Oct/Oct', getline(1))
+  call assert_fails('call feedkeys("A\<c-x>\<c-u>/\<esc>", "tx")', 'E565:')
+  call assert_equal('Jan/', getline(1))
   bwipe!
   set completefunc=
 endfunc
diff --git a/src/nvim/testdir/test_quickfix.vim b/src/nvim/testdir/test_quickfix.vim
index 290fc488f1..ddd4229f17 100644
--- a/src/nvim/testdir/test_quickfix.vim
+++ b/src/nvim/testdir/test_quickfix.vim
@@ -3143,7 +3143,7 @@ endfunc
 func Test_vimgrep_with_textlock()
   new
 
-  " Simple way to execute something with "textwinlock" set.
+  " Simple way to execute something with "textlock" set.
   " Check that vimgrep without jumping can be executed.
   au InsertCharPre * vimgrep /RunTheTest/j runtest.vim
   normal ax