fix(messages): recognize cmdline one_key/number prompt State (#34206)

Problem:  Since 48e2a736, prompt messages are handled by an actual
          active cmdline, resulting in `State` no longer being equal
          to `MODE_CONFIRM` which is used in some places. E.g. to
          specify the current `mode()` or to re-emit a confirm message.
Solution: Replace `MODE_CONFIRM` with a new `MODE_CMDLINE` sub-mode when
          `ccline.one_key/mouse_used` is set. Use it to avoid clearing
          mouse_used prompt messages, and to re-emit one_key messages
          (when ext_messages is inactive, for which this is unnecessary).

src/nvim/drawscreen.c

@@ -266,12 +266,19 @@ void screenclear(void)
   }
 }
 
+/// Unlike cmdline "one_key" prompts, the message part of the prompt is not stored
+/// to be re-emitted: avoid clearing the prompt from the message grid.
+static bool cmdline_number_prompt(void)
+{
+  return !ui_has(kUIMessages) && State == MODE_CMDLINE && get_cmdline_info()->mouse_used != NULL;
+}
+
 /// Set dimensions of the Nvim application "screen".
 void screen_resize(int width, int height)
 {
   // Avoid recursiveness, can happen when setting the window size causes
   // another window-changed signal.
-  if (updating_screen || resizing_screen) {
+  if (updating_screen || resizing_screen || cmdline_number_prompt()) {
     return;
   }
 
@@ -348,7 +355,7 @@ void screen_resize(int width, int height)
   resizing_autocmd = false;
   redraw_all_later(UPD_CLEAR);
 
-  if (State != MODE_ASKMORE && State != MODE_EXTERNCMD && State != MODE_CONFIRM) {
+  if (State != MODE_ASKMORE && State != MODE_EXTERNCMD) {
     screenclear();
   }
 
@@ -364,8 +371,11 @@ void screen_resize(int width, int height)
     // - While editing the command line, only redraw that. TODO: lies
     // - in Ex mode, don't redraw anything.
     // - Otherwise, redraw right now, and position the cursor.
-    if (State == MODE_ASKMORE || State == MODE_EXTERNCMD || State == MODE_CONFIRM
-        || exmode_active) {
+    if (State == MODE_ASKMORE || State == MODE_EXTERNCMD || exmode_active
+        || (State == MODE_CMDLINE && get_cmdline_info()->one_key)) {
+      if (State == MODE_CMDLINE) {
+        update_screen();
+      }
       if (msg_grid.chars) {
         msg_grid_validate();
       }
@@ -451,7 +461,7 @@ int update_screen(void)
 
   // Postpone the redrawing when it's not needed and when being called
   // recursively.
-  if (!redrawing() || updating_screen) {
+  if (!redrawing() || updating_screen || cmdline_number_prompt()) {
     return FAIL;
   }
 
@@ -490,7 +500,7 @@ int update_screen(void)
   }
 
   // if the screen was scrolled up when displaying a message, scroll it down
-  if (msg_scrolled || msg_grid_invalid) {
+  if ((msg_scrolled || msg_grid_invalid) && !cmdline_number_prompt()) {
     clear_cmdline = true;
     int valid = MAX(Rows - msg_scrollsize(), 0);
     if (msg_grid.chars) {
@@ -697,6 +707,7 @@ int update_screen(void)
   if (still_may_intro) {
     intro_message(false);
   }
+  repeat_message();
 
   decor_providers_invoke_end();
 

src/nvim/ex_cmds.c

@@ -3716,12 +3716,7 @@ static int do_sub(exarg_T *eap, const proftime_T timeout, const int cmdpreview_n
 
         if (subflags.do_ask && cmdpreview_ns <= 0) {
           int typed = 0;
-
-          // change State to MODE_CONFIRM, so that the mouse works
-          // properly
           int save_State = State;
-          State = MODE_CONFIRM;
-          setmouse();                   // disable mouse in xterm
           curwin->w_cursor.col = regmatch.startpos[0].col;
 
           if (curwin->w_p_crb) {

src/nvim/getchar.c

@@ -2197,7 +2197,6 @@ static int handle_mapping(int *keylenp, const bool *timedout, int *mapdepth)
       && !(p_paste && (State & (MODE_INSERT | MODE_CMDLINE)))
       && !(State == MODE_HITRETURN && (tb_c1 == CAR || tb_c1 == ' '))
       && State != MODE_ASKMORE
-      && State != MODE_CONFIRM
       && !at_ins_compl_key()) {
     int mlen;
     int nolmaplen;

src/nvim/input.c

@@ -41,8 +41,6 @@ int ask_yesno(const char *const str)
   const int save_State = State;
 
   no_wait_return++;
-  State = MODE_CONFIRM;  // Mouse behaves like with :confirm.
-  setmouse();  // Disable mouse in xterm.
   snprintf(IObuff, IOSIZE, _("%s (y/n)?"), str);
   char *prompt = xstrdup(IObuff);
 

src/nvim/message.c

@@ -29,6 +29,7 @@
 #include "nvim/ex_cmds_defs.h"
 #include "nvim/ex_docmd.h"
 #include "nvim/ex_eval.h"
+#include "nvim/ex_getln.h"
 #include "nvim/fileio.h"
 #include "nvim/garray.h"
 #include "nvim/garray_defs.h"
@@ -3072,13 +3073,17 @@ void msg_moremsg(bool full)
 }
 
 /// Repeat the message for the current mode: MODE_ASKMORE, MODE_EXTERNCMD,
-/// MODE_CONFIRM or exmode_active.
+/// confirm() prompt or exmode_active.
 void repeat_message(void)
 {
+  if (ui_has(kUIMessages)) {
+    return;
+  }
+
   if (State == MODE_ASKMORE) {
     msg_moremsg(true);          // display --more-- message again
     msg_row = Rows - 1;
-  } else if (State == MODE_CONFIRM) {
+  } else if (State == MODE_CMDLINE && confirm_msg != NULL) {
     display_confirm_msg();      // display ":confirm" message again
     msg_row = Rows - 1;
   } else if (State == MODE_EXTERNCMD) {
@@ -3550,8 +3555,6 @@ int do_dialog(int type, const char *title, const char *message, const char *butt
   int oldState = State;
 
   msg_silent = 0;  // If dialog prompts for input, user needs to see it! #8788
-  State = MODE_CONFIRM;
-  setmouse();
 
   // Since we wait for a keypress, don't make the
   // user press RETURN as well afterwards.
@@ -3608,6 +3611,8 @@ int do_dialog(int type, const char *title, const char *message, const char *butt
   }
 
   xfree(hotkeys);
+  xfree(confirm_msg);
+  confirm_msg = NULL;
 
   msg_silent = save_msg_silent;
   State = oldState;
@@ -3688,7 +3693,6 @@ static char *console_dialog_alloc(const char *message, const char *buttons, bool
   }
 
   // Now allocate space for the strings
-  xfree(confirm_msg);
   confirm_msg = xmalloc((size_t)msg_len);
   snprintf(confirm_msg, (size_t)msg_len, "\n%s\n", message);
 

src/nvim/state.c

@@ -184,12 +184,12 @@ void get_mode(char *buf)
 {
   int i = 0;
 
-  if (State == MODE_HITRETURN || State == MODE_ASKMORE
-      || State == MODE_SETWSIZE || State == MODE_CONFIRM) {
+  if (State == MODE_HITRETURN || State == MODE_ASKMORE || State == MODE_SETWSIZE
+      || (State == MODE_CMDLINE && get_cmdline_info()->one_key)) {
     buf[i++] = 'r';
     if (State == MODE_ASKMORE) {
       buf[i++] = 'm';
-    } else if (State == MODE_CONFIRM) {
+    } else if (State == MODE_CMDLINE) {
       buf[i++] = '?';
     }
   } else if (State == MODE_EXTERNCMD) {

src/nvim/state_defs.h

@@ -41,5 +41,4 @@ enum {
   MODE_SETWSIZE    = 0x4000,  ///< window size has changed
   MODE_EXTERNCMD   = 0x5000,  ///< executing an external command
   MODE_SHOWMATCH   = 0x6000 | MODE_INSERT,  ///< show matching paren
-  MODE_CONFIRM     = 0x7000,  ///< ":confirm" prompt
 };

src/nvim/ui.c

@@ -613,8 +613,8 @@ void ui_check_mouse(void)
     checkfor = MOUSE_INSERT;
   } else if (State & MODE_CMDLINE) {
     checkfor = MOUSE_COMMAND;
-  } else if (State == MODE_CONFIRM || State == MODE_EXTERNCMD) {
-    checkfor = ' ';  // don't use mouse for ":confirm" or ":!cmd"
+  } else if (State == MODE_EXTERNCMD) {
+    checkfor = ' ';  // don't use mouse for ":!cmd"
   }
 
   // mouse should be active if at least one of the following is true: