fix(api): use text_locked() to check textlock

Problem: some API functions that check textlock (usually those that can change
curwin or curbuf) can break the cmdwin.

Solution: make FUNC_API_CHECK_TEXTLOCK call text_locked() instead, which already
checks for textlock, cmdwin and `<expr>` status.

Add FUNC_API_TEXTLOCK_ALLOW_CMDWIN to allow such functions to be usable in the
cmdwin if they can work properly there; the opt-in nature of this attribute
should hopefully help mitigate future bugs.

Also fix a regression in #22634 that made functions checking textlock usable in
`<expr>` mappings, and rename FUNC_API_CHECK_TEXTLOCK to FUNC_API_TEXTLOCK.

11 files changed, 67 insertions, 31 deletions

diff --git a/runtime/doc/api.txt b/runtime/doc/api.txt
index 87ea000047..203468cc8a 100644
--- a/runtime/doc/api.txt
+++ b/runtime/doc/api.txt
@@ -1365,7 +1365,7 @@ nvim_set_current_buf({buffer})                        *nvim_set_current_buf()*
     Sets the current buffer.
 
     Attributes: ~
-        not allowed when |textlock| is active
+        not allowed when |textlock| is active or in the |cmdwin|
 
     Parameters: ~
       • {buffer}  Buffer handle
@@ -1389,7 +1389,7 @@ nvim_set_current_tabpage({tabpage})               *nvim_set_current_tabpage()*
     Sets the current tabpage.
 
     Attributes: ~
-        not allowed when |textlock| is active
+        not allowed when |textlock| is active or in the |cmdwin|
 
     Parameters: ~
       • {tabpage}  Tabpage handle
@@ -1398,7 +1398,7 @@ nvim_set_current_win({window})                        *nvim_set_current_win()*
     Sets the current window.
 
     Attributes: ~
-        not allowed when |textlock| is active
+        not allowed when |textlock| is active or in the |cmdwin|
 
     Parameters: ~
       • {window}  Window handle
@@ -2163,7 +2163,7 @@ nvim_buf_delete({buffer}, {opts})                          *nvim_buf_delete()*
     Deletes the buffer. See |:bwipeout|
 
     Attributes: ~
-        not allowed when |textlock| is active
+        not allowed when |textlock| is active or in the |cmdwin|
 
     Parameters: ~
       • {buffer}  Buffer handle, or 0 for current buffer
@@ -2894,7 +2894,7 @@ nvim_win_hide({window})                                      *nvim_win_hide()*
     or |nvim_win_close()|, which will close the buffer.
 
     Attributes: ~
-        not allowed when |textlock| is active
+        not allowed when |textlock| is active or in the |cmdwin|
 
     Parameters: ~
       • {window}  Window handle, or 0 for current window
@@ -2912,7 +2912,7 @@ nvim_win_set_buf({window}, {buffer})                      *nvim_win_set_buf()*
     Sets the current buffer in a window, without side effects
 
     Attributes: ~
-        not allowed when |textlock| is active
+        not allowed when |textlock| is active or in the |cmdwin|
 
     Parameters: ~
       • {window}  Window handle, or 0 for current window
@@ -2999,7 +2999,7 @@ nvim_open_win({buffer}, {enter}, {*config})                  *nvim_open_win()*
 <
 
     Attributes: ~
-        not allowed when |textlock| is active
+        not allowed when |textlock| is active or in the |cmdwin|
 
     Parameters: ~
       • {buffer}  Buffer to display, or 0 for current buffer
diff --git a/scripts/gen_vimdoc.py b/scripts/gen_vimdoc.py
index 96db0d1aad..8410a3b5b1 100755
--- a/scripts/gen_vimdoc.py
+++ b/scripts/gen_vimdoc.py
@@ -310,7 +310,8 @@ param_exclude = (
 # Annotations are displayed as line items after API function descriptions.
 annotation_map = {
     'FUNC_API_FAST': '|api-fast|',
-    'FUNC_API_CHECK_TEXTLOCK': 'not allowed when |textlock| is active',
+    'FUNC_API_TEXTLOCK': 'not allowed when |textlock| is active or in the |cmdwin|',
+    'FUNC_API_TEXTLOCK_ALLOW_CMDWIN': 'not allowed when |textlock| is active',
     'FUNC_API_REMOTE_ONLY': '|RPC| only',
     'FUNC_API_LUA_ONLY': 'Lua |vim.api| only',
 }
diff --git a/src/nvim/api/buffer.c b/src/nvim/api/buffer.c
index 8774aee20b..7cd9686544 100644
--- a/src/nvim/api/buffer.c
+++ b/src/nvim/api/buffer.c
@@ -347,7 +347,7 @@ end:
 void nvim_buf_set_lines(uint64_t channel_id, Buffer buffer, Integer start, Integer end,
                         Boolean strict_indexing, ArrayOf(String) replacement, Error *err)
   FUNC_API_SINCE(1)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK_ALLOW_CMDWIN
 {
   buf_T *buf = find_buffer_by_handle(buffer, err);
 
@@ -1061,7 +1061,7 @@ Boolean nvim_buf_is_loaded(Buffer buffer)
 ///          - unload: Unloaded only, do not delete. See |:bunload|
 void nvim_buf_delete(Buffer buffer, Dictionary opts, Error *err)
   FUNC_API_SINCE(7)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK
 {
   buf_T *buf = find_buffer_by_handle(buffer, err);
 
diff --git a/src/nvim/api/vim.c b/src/nvim/api/vim.c
index 8d34a34e8a..eacc833c58 100644
--- a/src/nvim/api/vim.c
+++ b/src/nvim/api/vim.c
@@ -612,7 +612,7 @@ String nvim_get_current_line(Error *err)
 /// @param[out] err Error details, if any
 void nvim_set_current_line(String line, Error *err)
   FUNC_API_SINCE(1)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK_ALLOW_CMDWIN
 {
   buffer_set_line(curbuf->handle, curwin->w_cursor.lnum - 1, line, err);
 }
@@ -622,7 +622,7 @@ void nvim_set_current_line(String line, Error *err)
 /// @param[out] err Error details, if any
 void nvim_del_current_line(Error *err)
   FUNC_API_SINCE(1)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK_ALLOW_CMDWIN
 {
   buffer_del_line(curbuf->handle, curwin->w_cursor.lnum - 1, err);
 }
@@ -803,7 +803,7 @@ Buffer nvim_get_current_buf(void)
 /// @param[out] err Error details, if any
 void nvim_set_current_buf(Buffer buffer, Error *err)
   FUNC_API_SINCE(1)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK
 {
   buf_T *buf = find_buffer_by_handle(buffer, err);
 
@@ -858,7 +858,7 @@ Window nvim_get_current_win(void)
 /// @param[out] err Error details, if any
 void nvim_set_current_win(Window window, Error *err)
   FUNC_API_SINCE(1)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK
 {
   win_T *win = find_window_by_handle(window, err);
 
@@ -1084,7 +1084,7 @@ Tabpage nvim_get_current_tabpage(void)
 /// @param[out] err Error details, if any
 void nvim_set_current_tabpage(Tabpage tabpage, Error *err)
   FUNC_API_SINCE(1)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK
 {
   tabpage_T *tp = find_tab_by_handle(tabpage, err);
 
@@ -1126,7 +1126,7 @@ void nvim_set_current_tabpage(Tabpage tabpage, Error *err)
 ///     - false: Client must cancel the paste.
 Boolean nvim_paste(String data, Boolean crlf, Integer phase, Error *err)
   FUNC_API_SINCE(6)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK_ALLOW_CMDWIN
 {
   static bool draining = false;
   bool cancel = false;
@@ -1197,7 +1197,7 @@ theend:
 /// @param[out] err Error details, if any
 void nvim_put(ArrayOf(String) lines, String type, Boolean after, Boolean follow, Error *err)
   FUNC_API_SINCE(6)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK_ALLOW_CMDWIN
 {
   yankreg_T *reg = xcalloc(1, sizeof(yankreg_T));
   VALIDATE_S((prepare_yankreg_from_object(reg, type, lines.size)), "type", type.data, {
diff --git a/src/nvim/api/win_config.c b/src/nvim/api/win_config.c
index 8e4fbb6779..6ca36a0daf 100644
--- a/src/nvim/api/win_config.c
+++ b/src/nvim/api/win_config.c
@@ -158,7 +158,7 @@
 /// @return Window handle, or 0 on error
 Window nvim_open_win(Buffer buffer, Boolean enter, Dict(float_config) *config, Error *err)
   FUNC_API_SINCE(6)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK
 {
   FloatConfig fconfig = FLOAT_CONFIG_INIT;
   if (!parse_float_config(config, &fconfig, false, true, err)) {
diff --git a/src/nvim/api/window.c b/src/nvim/api/window.c
index e5a824fec9..5fb07ecbc8 100644
--- a/src/nvim/api/window.c
+++ b/src/nvim/api/window.c
@@ -48,7 +48,7 @@ Buffer nvim_win_get_buf(Window window, Error *err)
 /// @param[out] err Error details, if any
 void nvim_win_set_buf(Window window, Buffer buffer, Error *err)
   FUNC_API_SINCE(5)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK
 {
   win_set_buf(window, buffer, false, err);
 }
@@ -351,7 +351,7 @@ Boolean nvim_win_is_valid(Window window)
 /// @param[out] err Error details, if any
 void nvim_win_hide(Window window, Error *err)
   FUNC_API_SINCE(7)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK
 {
   win_T *win = find_window_by_handle(window, err);
   if (!win) {
@@ -383,7 +383,7 @@ void nvim_win_hide(Window window, Error *err)
 /// @param[out] err Error details, if any
 void nvim_win_close(Window window, Boolean force, Error *err)
   FUNC_API_SINCE(6)
-  FUNC_API_CHECK_TEXTLOCK
+  FUNC_API_TEXTLOCK_ALLOW_CMDWIN
 {
   win_T *win = find_window_by_handle(window, err);
   if (!win) {
diff --git a/src/nvim/func_attr.h b/src/nvim/func_attr.h
index 57e5766f67..9ac4ee28d6 100644
--- a/src/nvim/func_attr.h
+++ b/src/nvim/func_attr.h
@@ -226,8 +226,10 @@
 # define FUNC_API_REMOTE_ONLY
 /// API function not exposed in Vimscript/remote.
 # define FUNC_API_LUA_ONLY
-/// API function checked textlock.
-# define FUNC_API_CHECK_TEXTLOCK
+/// API function fails during textlock.
+# define FUNC_API_TEXTLOCK
+/// API function fails during textlock, but allows cmdwin.
+# define FUNC_API_TEXTLOCK_ALLOW_CMDWIN
 /// API function introduced at the given API level.
 # define FUNC_API_SINCE(X)
 /// API function deprecated since the given API level.
diff --git a/src/nvim/generators/c_grammar.lua b/src/nvim/generators/c_grammar.lua
index d83658e977..f33da452ff 100644
--- a/src/nvim/generators/c_grammar.lua
+++ b/src/nvim/generators/c_grammar.lua
@@ -47,7 +47,8 @@ local c_proto = Ct(
   (fill * Cg((P('FUNC_API_NOEXPORT') * Cc(true)), 'noexport') ^ -1) *
   (fill * Cg((P('FUNC_API_REMOTE_ONLY') * Cc(true)), 'remote_only') ^ -1) *
   (fill * Cg((P('FUNC_API_LUA_ONLY') * Cc(true)), 'lua_only') ^ -1) *
-  (fill * Cg((P('FUNC_API_CHECK_TEXTLOCK') * Cc(true)), 'check_textlock') ^ -1) *
+  (fill * (Cg(P('FUNC_API_TEXTLOCK_ALLOW_CMDWIN') * Cc(true), 'textlock_allow_cmdwin') +
+           Cg(P('FUNC_API_TEXTLOCK') * Cc(true), 'textlock')) ^ -1) *
   (fill * Cg((P('FUNC_API_REMOTE_IMPL') * Cc(true)), 'remote_impl') ^ -1) *
   (fill * Cg((P('FUNC_API_COMPOSITOR_IMPL') * Cc(true)), 'compositor_impl') ^ -1) *
   (fill * Cg((P('FUNC_API_CLIENT_IMPL') * Cc(true)), 'client_impl') ^ -1) *
diff --git a/src/nvim/generators/gen_api_dispatch.lua b/src/nvim/generators/gen_api_dispatch.lua
index 244921de31..bf211f5273 100644
--- a/src/nvim/generators/gen_api_dispatch.lua
+++ b/src/nvim/generators/gen_api_dispatch.lua
@@ -210,10 +210,11 @@ local keysets_defs = io.open(keysets_outputf, 'wb')
 --  so that the dispatcher can find the C functions that you are creating!
 -- ===========================================================================
 output:write([[
+#include "nvim/ex_docmd.h"
+#include "nvim/ex_getln.h"
 #include "nvim/log.h"
 #include "nvim/map.h"
 #include "nvim/msgpack_rpc/helpers.h"
-#include "nvim/vim.h"
 
 #include "nvim/api/autocmd.h"
 #include "nvim/api/buffer.h"
@@ -389,8 +390,13 @@ for i = 1, #functions do
       args[#args + 1] = converted
     end
 
-    if fn.check_textlock then
-      output:write('\n  if (textlock != 0) {')
+    if fn.textlock then
+      output:write('\n  if (text_locked()) {')
+      output:write('\n    api_set_error(error, kErrorTypeException, "%s", get_text_locked_msg());')
+      output:write('\n    goto cleanup;')
+      output:write('\n  }\n')
+    elseif fn.textlock_allow_cmdwin then
+      output:write('\n  if (textlock != 0 || expr_map_locked()) {')
       output:write('\n    api_set_error(error, kErrorTypeException, "%s", e_textlock);')
       output:write('\n    goto cleanup;')
       output:write('\n  }\n')
@@ -525,6 +531,8 @@ output:write([[
 #include <lualib.h>
 #include <lauxlib.h>
 
+#include "nvim/ex_docmd.h"
+#include "nvim/ex_getln.h"
 #include "nvim/func_attr.h"
 #include "nvim/api/private/defs.h"
 #include "nvim/api/private/helpers.h"
@@ -565,9 +573,16 @@ local function process_function(fn)
     ]], fn.name))
   end
 
-  if fn.check_textlock then
+  if fn.textlock then
+    write_shifted_output(output, [[
+    if (text_locked()) {
+      api_set_error(&err, kErrorTypeException, "%s", get_text_locked_msg());
+      goto exit_0;
+    }
+    ]])
+  elseif fn.textlock_allow_cmdwin then
     write_shifted_output(output, [[
-    if (textlock != 0) {
+    if (textlock != 0 || expr_map_locked()) {
       api_set_error(&err, kErrorTypeException, "%s", e_textlock);
       goto exit_0;
     }
diff --git a/src/uncrustify.cfg b/src/uncrustify.cfg
index 32cf173741..8c07894779 100644
--- a/src/uncrustify.cfg
+++ b/src/uncrustify.cfg
@@ -3636,7 +3636,8 @@ set_numbering_for_html_output   = false    # true/false
 #       `macro-close END_MESSAGE_MAP`
 #
 #
-set CLASS_COLON                  FUNC_API_CHECK_TEXTLOCK
+set CLASS_COLON                  FUNC_API_TEXTLOCK
+set CLASS_COLON                  FUNC_API_TEXTLOCK_ALLOW_CMDWIN
 set CLASS_COLON                  FUNC_API_DEPRECATED_SINCE
 set CLASS_COLON                  FUNC_API_FAST
 set CLASS_COLON                  FUNC_API_LUA_ONLY
diff --git a/test/functional/vimscript/api_functions_spec.lua b/test/functional/vimscript/api_functions_spec.lua
index 14678a966d..683ae2446c 100644
--- a/test/functional/vimscript/api_functions_spec.lua
+++ b/test/functional/vimscript/api_functions_spec.lua
@@ -7,6 +7,7 @@ local exc_exec, expect, eval = helpers.exc_exec, helpers.expect, helpers.eval
 local insert, pcall_err = helpers.insert, helpers.pcall_err
 local matches = helpers.matches
 local meths = helpers.meths
+local feed = helpers.feed
 
 describe('eval-API', function()
   before_each(clear)
@@ -48,10 +49,25 @@ describe('eval-API', function()
     eq('Vim(call):E5555: API call: Invalid buffer id: 17', err)
   end)
 
-  it('cannot change texts if textlocked', function()
+  it('cannot change text or window if textlocked', function()
     command("autocmd TextYankPost <buffer> ++once call nvim_buf_set_lines(0, 0, -1, v:false, [])")
     matches('Vim%(call%):E5555: API call: E565: Not allowed to change text or change window$',
        pcall_err(command, "normal! yy"))
+
+    -- Functions checking textlock should also not be usable from <expr> mappings.
+    command("inoremap <expr> <f2> nvim_win_close(0, 1)")
+    eq('Vim(normal):E5555: API call: E565: Not allowed to change text or change window',
+       pcall_err(command, [[execute "normal i\<f2>"]]))
+
+    -- Some functions checking textlock (usually those that may change the current window or buffer)
+    -- also ought to not be usable in the cmdwin.
+    feed("q:")
+    eq('E11: Invalid in command-line window; <CR> executes, CTRL-C quits',
+       pcall_err(meths.win_hide, 0))
+
+    -- But others, like nvim_buf_set_lines(), which just changes text, is OK.
+    curbufmeths.set_lines(0, -1, 1, {"wow!"})
+    eq({'wow!'}, curbufmeths.get_lines(0, -1, 1))
   end)
 
   it("use buffer numbers and windows ids as handles", function()