diff --git a/runtime/doc/insert.txt b/runtime/doc/insert.txt
index d8bddce..8c35798 100644
--- a/runtime/doc/insert.txt
+++ b/runtime/doc/insert.txt
@@ -671,7 +671,7 @@
 ends CTRL-X mode (any key that is not a valid CTRL-X mode command) is mapped.
 Also, when doing completion with 'complete' mappings apply as usual.
 
-							*E578* *E565*
+								*E565*
 Note: While completion is active Insert mode can't be used recursively and
 buffer text cannot be changed.  Mappings that somehow invoke ":normal i.."
 will generate an E565 error.
diff --git a/runtime/doc/tags b/runtime/doc/tags
index b8fb359..c53ae5e 100644
--- a/runtime/doc/tags
+++ b/runtime/doc/tags
@@ -4749,7 +4749,6 @@
 E575	starting.txt	/*E575*
 E576	starting.txt	/*E576*
 E577	starting.txt	/*E577*
-E578	insert.txt	/*E578*
 E579	eval.txt	/*E579*
 E580	eval.txt	/*E580*
 E581	eval.txt	/*E581*
diff --git a/src/beval.c b/src/beval.c
index a9d10a2..4b89af3 100644
--- a/src/beval.c
+++ b/src/beval.c
@@ -284,7 +284,7 @@
 	    curbuf = save_curbuf;
 	    if (use_sandbox)
 		++sandbox;
-	    ++textwinlock;
+	    ++textlock;
 
 	    if (bexpr == p_bexpr)
 	    {
@@ -311,7 +311,7 @@
 
 	    if (use_sandbox)
 		--sandbox;
-	    --textwinlock;
+	    --textlock;
 	    current_sctx = save_sctx;
 
 	    set_vim_var_string(VV_BEVAL_TEXT, NULL, -1);
diff --git a/src/change.c b/src/change.c
index b653dcc..a9927e0 100644
--- a/src/change.c
+++ b/src/change.c
@@ -324,7 +324,7 @@
 	    next = lnr->lr_next;
 	    if (lnr->lr_id == id)
 	    {
-		if (textwinlock > 0)
+		if (textlock > 0)
 		{
 		    // in invoke_listeners(), clear ID and delete later
 		    lnr->lr_id = 0;
@@ -401,7 +401,7 @@
 
     argv[4].v_type = VAR_LIST;
     argv[4].vval.v_list = buf->b_recorded_changes;
-    ++textwinlock;
+    ++textlock;
 
     for (lnr = buf->b_listener; lnr != NULL; lnr = lnr->lr_next)
     {
@@ -421,7 +421,7 @@
 	    prev = lnr;
     }
 
-    --textwinlock;
+    --textlock;
     list_unref(buf->b_recorded_changes);
     buf->b_recorded_changes = NULL;
 
diff --git a/src/edit.c b/src/edit.c
index 939aeb9..443e023 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -168,8 +168,7 @@
     // Don't allow changes in the buffer while editing the cmdline.  The
     // caller of getcmdline() may get confused.
     // Don't allow recursive insert mode when busy with completion.
-    if (textwinlock != 0 || textlock != 0
-			  || ins_compl_active() || compl_busy || pum_visible())
+    if (textlock != 0 || ins_compl_active() || compl_busy || pum_visible())
     {
 	emsg(_(e_not_allowed_to_change_text_or_change_window));
 	return FALSE;
@@ -5342,7 +5341,7 @@
     }
 
     // Lock the text to avoid weird things from happening.
-    ++textwinlock;
+    ++textlock;
     set_vim_var_string(VV_CHAR, buf, -1);  // set v:char
 
     res = NULL;
@@ -5356,7 +5355,7 @@
     }
 
     set_vim_var_string(VV_CHAR, NULL, -1);  // clear v:char
-    --textwinlock;
+    --textlock;
 
     // Restore the State, it may have been changed.
     State = save_State;
diff --git a/src/errors.h b/src/errors.h
index c819729..4e02986 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -1458,8 +1458,7 @@
 EXTERN char e_illegal_register_name[]
 	INIT(= N_("Illegal register name"));
 #endif
-EXTERN char e_not_allowed_to_change_text_here[]
-	INIT(= N_("E578: Not allowed to change text here"));
+// E578 unused
 #ifdef FEAT_EVAL
 EXTERN char e_if_nesting_too_deep[]
 	INIT(= N_("E579: :if nesting too deep"));
diff --git a/src/eval.c b/src/eval.c
index 1aa0eae..2c70c3b 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -543,7 +543,7 @@
 
 /*
  * Call eval_to_string() without using current local variables and using
- * textwinlock.  When "use_sandbox" is TRUE use the sandbox.
+ * textlock.  When "use_sandbox" is TRUE use the sandbox.
  * Use legacy Vim script syntax.
  */
     char_u *
@@ -562,12 +562,12 @@
     save_funccal(&funccal_entry);
     if (use_sandbox)
 	++sandbox;
-    ++textwinlock;
+    ++textlock;
     may_garbage_collect = FALSE;
     retval = eval_to_string(arg, FALSE);
     if (use_sandbox)
 	--sandbox;
-    --textwinlock;
+    --textlock;
     may_garbage_collect = save_garbage;
     restore_funccal();
     current_sctx.sc_version = save_sc_version;
@@ -807,7 +807,7 @@
     ++emsg_off;
     if (use_sandbox)
 	++sandbox;
-    ++textwinlock;
+    ++textlock;
     *cp = NUL;
     if (eval0(arg, &tv, NULL, &EVALARG_EVALUATE) == FAIL)
 	retval = 0;
@@ -832,7 +832,7 @@
     --emsg_off;
     if (use_sandbox)
 	--sandbox;
-    --textwinlock;
+    --textlock;
     clear_evalarg(&EVALARG_EVALUATE, NULL);
     current_sctx = saved_sctx;
 
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index 210e21f..4a6073d 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -4414,14 +4414,14 @@
 		subflags_save = subflags;
 
 		// Disallow changing text or switching window in an expression.
-		++textwinlock;
+		++textlock;
 #endif
 		// get length of substitution part
 		sublen = vim_regsub_multi(&regmatch,
 				    sub_firstlnum - regmatch.startpos[0].lnum,
 			       sub, sub_firstline, FALSE, magic_isset(), TRUE);
 #ifdef FEAT_EVAL
-		--textwinlock;
+		--textlock;
 
 		// If getting the substitute string caused an error, don't do
 		// the replacement.
@@ -4524,13 +4524,13 @@
 		new_end += copy_len;
 
 #ifdef FEAT_EVAL
-		++textwinlock;
+		++textlock;
 #endif
 		(void)vim_regsub_multi(&regmatch,
 				    sub_firstlnum - regmatch.startpos[0].lnum,
 				      sub, new_end, TRUE, magic_isset(), TRUE);
 #ifdef FEAT_EVAL
-		--textwinlock;
+		--textlock;
 #endif
 		sub_nsubs++;
 		did_sub = TRUE;
diff --git a/src/ex_getln.c b/src/ex_getln.c
index 6462b00..9dadfbf 100644
--- a/src/ex_getln.c
+++ b/src/ex_getln.c
@@ -850,12 +850,12 @@
 	c = get_expr_register();
 	if (c == '=')
 	{
-	    // Need to save and restore ccline.  And set "textwinlock"
+	    // Need to save and restore ccline.  And set "textlock"
 	    // to avoid nasty things like going to another buffer when
 	    // evaluating an expression.
-	    ++textwinlock;
+	    ++textlock;
 	    p = get_expr_line();
-	    --textwinlock;
+	    --textlock;
 
 	    if (p != NULL)
 	    {
@@ -2710,13 +2710,13 @@
  * 'balloonexpr', etc.
  */
     int
-text_and_win_locked(void)
+text_locked(void)
 {
 #ifdef FEAT_CMDWIN
     if (cmdwin_type != 0)
 	return TRUE;
 #endif
-    return textwinlock != 0;
+    return textlock != 0;
 }
 
 /*
@@ -2736,19 +2736,7 @@
     if (cmdwin_type != 0)
 	return e_invalid_in_cmdline_window;
 #endif
-    if (textwinlock != 0)
-	return e_not_allowed_to_change_text_or_change_window;
-    return e_not_allowed_to_change_text_here;
-}
-
-/*
- * Return TRUE when the text must not be changed and/or we cannot switch to
- * another window.  TRUE while evaluating 'completefunc'.
- */
-    int
-text_locked(void)
-{
-    return text_and_win_locked() || textlock != 0;
+    return e_not_allowed_to_change_text_or_change_window;
 }
 
 /*
@@ -3730,11 +3718,11 @@
     regname = may_get_selection(regname);
 #endif
 
-    // Need to  set "textwinlock" to avoid nasty things like going to another
+    // Need to set "textlock" to avoid nasty things like going to another
     // buffer when evaluating an expression.
-    ++textwinlock;
+    ++textlock;
     i = get_spec_reg(regname, &arg, &allocated, TRUE);
-    --textwinlock;
+    --textlock;
 
     if (i)
     {
diff --git a/src/globals.h b/src/globals.h
index bf098fd..3861e80 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -846,16 +846,11 @@
 				// allowed, e.g. when sourcing .exrc or .vimrc
 				// in current directory
 
-EXTERN int	textwinlock INIT(= 0);
+EXTERN int	textlock INIT(= 0);
 				// non-zero when changing text and jumping to
 				// another window or editing another buffer is
 				// not allowed
 
-EXTERN int	textlock INIT(= 0);
-				// non-zero when changing text is not allowed,
-				// jumping to another window is allowed,
-				// editing another buffer is not allowed.
-
 EXTERN int	curbuf_lock INIT(= 0);
 				// non-zero when the current buffer can't be
 				// changed.  Used for FileChangedRO.
diff --git a/src/indent.c b/src/indent.c
index ccf4aa8..7598c1c 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -1872,7 +1872,7 @@
     set_vim_var_nr(VV_LNUM, curwin->w_cursor.lnum);
     if (use_sandbox)
 	++sandbox;
-    ++textwinlock;
+    ++textlock;
     current_sctx = curbuf->b_p_script_ctx[BV_INDE];
 
     // Need to make a copy, the 'indentexpr' option could be changed while
@@ -1886,7 +1886,7 @@
 
     if (use_sandbox)
 	--sandbox;
-    --textwinlock;
+    --textlock;
     current_sctx = save_sctx;
 
     // Restore the cursor position so that 'indentexpr' doesn't need to.
diff --git a/src/insexpand.c b/src/insexpand.c
index 89e0ebd..20df1b0 100644
--- a/src/insexpand.c
+++ b/src/insexpand.c
@@ -1144,9 +1144,9 @@
     dict_set_items_ro(v_event);
 
     recursive = TRUE;
-    textwinlock++;
+    textlock++;
     apply_autocmds(EVENT_COMPLETECHANGED, NULL, NULL, FALSE, curbuf);
-    textwinlock--;
+    textlock--;
     recursive = FALSE;
 
     restore_v_event(v_event, &save_v_event);
@@ -2643,7 +2643,7 @@
     // 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.
-    ++textwinlock;
+    ++textlock;
 
     cb = get_insert_callback(type);
     retval = call_callback(cb, 0, &rettv, 2, args);
@@ -2669,7 +2669,7 @@
 		break;
 	}
     }
-    --textwinlock;
+    --textlock;
 
     curwin->w_cursor = pos;	// restore the cursor position
     validate_cursor();
@@ -2867,7 +2867,6 @@
 f_complete(typval_T *argvars, typval_T *rettv UNUSED)
 {
     int	    startcol;
-    int	    save_textlock = textlock;
 
     if (in_vim9script()
 	    && (check_for_number_arg(argvars, 0) == FAIL
@@ -2880,10 +2879,6 @@
 	return;
     }
 
-    // "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())
@@ -2897,7 +2892,6 @@
 	if (startcol > 0)
 	    set_completion(startcol - 1, argvars[1].vval.v_list);
     }
-    textlock = save_textlock;
 }
 
 /*
@@ -4508,10 +4502,10 @@
     args[1].vval.v_string = (char_u *)"";
     args[2].v_type = VAR_UNKNOWN;
     pos = curwin->w_cursor;
-    ++textwinlock;
+    ++textlock;
     cb = get_insert_callback(ctrl_x_mode);
     col = call_callback_retnr(cb, 2, args);
-    --textwinlock;
+    --textlock;
 
     State = save_State;
     curwin->w_cursor = pos;	// restore the cursor position
diff --git a/src/map.c b/src/map.c
index a93cb2e..228d073 100644
--- a/src/map.c
+++ b/src/map.c
@@ -1695,7 +1695,7 @@
 
     // Forbid changing text or using ":normal" to avoid most of the bad side
     // effects.  Also restore the cursor position.
-    ++textwinlock;
+    ++textlock;
     ++ex_normal_lock;
     set_vim_var_char(c);  // set v:char to the typed character
     save_cursor = curwin->w_cursor;
@@ -1710,7 +1710,7 @@
     // Note: the evaluation may make "mp" invalid.
     p = eval_to_string(expr, FALSE);
 
-    --textwinlock;
+    --textlock;
     --ex_normal_lock;
     curwin->w_cursor = save_cursor;
     msg_col = save_msg_col;
diff --git a/src/proto/ex_getln.pro b/src/proto/ex_getln.pro
index 374b0a1..8c8bd0e 100644
--- a/src/proto/ex_getln.pro
+++ b/src/proto/ex_getln.pro
@@ -3,7 +3,6 @@
 char_u *getcmdline(int firstc, long count, int indent, getline_opt_T do_concat);
 char_u *getcmdline_prompt(int firstc, char_u *prompt, int attr, int xp_context, char_u *xp_arg);
 int check_opt_wim(void);
-int text_and_win_locked(void);
 void text_locked_msg(void);
 char *get_text_locked_msg(void);
 int text_locked(void);
diff --git a/src/register.c b/src/register.c
index d5a56ae..93860ba 100644
--- a/src/register.c
+++ b/src/register.c
@@ -1055,9 +1055,9 @@
     dict_set_items_ro(v_event);
 
     recursive = TRUE;
-    textwinlock++;
+    textlock++;
     apply_autocmds(EVENT_TEXTYANKPOST, NULL, NULL, FALSE, curbuf);
-    textwinlock--;
+    textlock--;
     recursive = FALSE;
 
     // Empty the dictionary, v:event is still valid
diff --git a/src/testdir/test_edit.vim b/src/testdir/test_edit.vim
index f8749f8..d56ee62 100644
--- a/src/testdir/test_edit.vim
+++ b/src/testdir/test_edit.vim
@@ -1041,7 +1041,7 @@
   set completefunc=CompleteFunc
   call setline(1, ['', 'abcd', ''])
   2d
-  call assert_fails("normal 2G$a\<C-X>\<C-U>", 'E578:')
+  call assert_fails("normal 2G$a\<C-X>\<C-U>", 'E565:')
   bwipe!
 endfunc
 
diff --git a/src/testdir/test_ins_complete.vim b/src/testdir/test_ins_complete.vim
index 5ae8908..365c646 100644
--- a/src/testdir/test_ins_complete.vim
+++ b/src/testdir/test_ins_complete.vim
@@ -698,7 +698,7 @@
   endfunc
   set completefunc=CompleteFunc
   call setline(1, ['', 'abcd', ''])
-  call assert_fails('exe "normal 2G$a\<C-X>\<C-U>"', 'E578:')
+  call assert_fails('exe "normal 2G$a\<C-X>\<C-U>"', 'E565:')
 
   " delete text when called for the second time
   func CompleteFunc2(findstart, base)
@@ -710,7 +710,7 @@
   endfunc
   set completefunc=CompleteFunc2
   call setline(1, ['', 'abcd', ''])
-  call assert_fails('exe "normal 2G$a\<C-X>\<C-U>"', 'E578:')
+  call assert_fails('exe "normal 2G$a\<C-X>\<C-U>"', 'E565:')
 
   " Jump to a different window from the complete function
   func CompleteFunc3(findstart, base)
diff --git a/src/testdir/test_popup.vim b/src/testdir/test_popup.vim
index 9832ccf..c389f63 100644
--- a/src/testdir/test_popup.vim
+++ b/src/testdir/test_popup.vim
@@ -655,7 +655,7 @@
   set completefunc=MessComplete
   new
   call setline(1, 'Ju')
-  call assert_fails('call feedkeys("A\<c-x>\<c-u>/\<esc>", "tx")', 'E578:')
+  call assert_fails('call feedkeys("A\<c-x>\<c-u>/\<esc>", "tx")', 'E565:')
   call assert_equal('Jan/', getline(1))
   bwipe!
   set completefunc=
diff --git a/src/testdir/test_quickfix.vim b/src/testdir/test_quickfix.vim
index 6970bdc..182d570 100644
--- a/src/testdir/test_quickfix.vim
+++ b/src/testdir/test_quickfix.vim
@@ -3474,7 +3474,7 @@
 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
diff --git a/src/undo.c b/src/undo.c
index 81cc28e..7ebad1c 100644
--- a/src/undo.c
+++ b/src/undo.c
@@ -331,9 +331,9 @@
 
     // Don't allow changes in the buffer while editing the cmdline.  The
     // caller of getcmdline() may get confused.
-    if (textwinlock != 0 || textlock != 0)
+    if (textlock != 0)
     {
-	emsg(_(e_not_allowed_to_change_text_here));
+	emsg(_(e_not_allowed_to_change_text_or_change_window));
 	return FALSE;
     }
 
diff --git a/src/version.c b/src/version.c
index 480ff28..cc9cb49 100644
--- a/src/version.c
+++ b/src/version.c
@@ -735,6 +735,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    5029,
+/**/
     5028,
 /**/
     5027,
diff --git a/src/window.c b/src/window.c
index 984fb46..fa59ade 100644
--- a/src/window.c
+++ b/src/window.c
@@ -4584,7 +4584,7 @@
 	return;
     }
 #endif
-    if (text_and_win_locked())
+    if (text_locked())
     {
 	beep_flush();
 	text_locked_msg();