1 files changed, 35 insertions, 11 deletions

diff --git a/src/nvim/tui/tui.c b/src/nvim/tui/tui.c
index b95a22d48b..4736e7a8ba 100644
--- a/src/nvim/tui/tui.c
+++ b/src/nvim/tui/tui.c
@@ -16,6 +16,11 @@
 #include "nvim/os/event.h"
 #include "nvim/tui/tui.h"
 
+// Space reserved in the output buffer to restore the cursor to normal when
+// flushing. No existing terminal will require 32 bytes to do that.
+#define CNORM_COMMAND_MAX_SIZE 32
+#define OUTBUF_SIZE 0xffff
+
 typedef struct term_input TermInput;
 
 #include "term_input.inl"
@@ -31,8 +36,8 @@ typedef struct {
 
 typedef struct {
   unibi_var_t params[9];
-  char buf[0xffff];
-  size_t bufpos;
+  char buf[OUTBUF_SIZE];
+  size_t bufpos, bufsize;
   TermInput *input;
   uv_loop_t *write_loop;
   unibi_term *ut;
@@ -45,6 +50,7 @@ typedef struct {
   int out_fd;
   int old_height;
   bool can_use_terminal_scroll;
+  bool busy;
   HlAttrs attrs, print_attrs;
   Cell **screen;
   struct {
@@ -86,6 +92,7 @@ void tui_start(void)
   data->fg = data->bg = -1;
   data->can_use_terminal_scroll = true;
   data->bufpos = 0;
+  data->bufsize = sizeof(data->buf) - CNORM_COMMAND_MAX_SIZE;
   data->unibi_ext.enable_mouse = -1;
   data->unibi_ext.disable_mouse = -1;
   data->unibi_ext.enable_bracketed_paste = -1;
@@ -134,8 +141,8 @@ void tui_start(void)
   ui->clear = tui_clear;
   ui->eol_clear = tui_eol_clear;
   ui->cursor_goto = tui_cursor_goto;
-  ui->cursor_on = tui_cursor_on;
-  ui->cursor_off = tui_cursor_off;
+  ui->busy_start = tui_busy_start;
+  ui->busy_stop = tui_busy_stop;
   ui->mouse_on = tui_mouse_on;
   ui->mouse_off = tui_mouse_off;
   ui->insert_mode = tui_insert_mode;
@@ -169,6 +176,7 @@ static void tui_stop(UI *ui)
   tui_normal_mode(ui);
   tui_mouse_off(ui);
   unibi_out(ui, unibi_exit_attribute_mode);
+  // cursor should be set to normal before exiting alternate screen
   unibi_out(ui, unibi_cursor_normal);
   unibi_out(ui, unibi_exit_ca_mode);
   // Disable bracketed paste
@@ -342,14 +350,14 @@ static void tui_cursor_goto(UI *ui, int row, int col)
   unibi_goto(ui, row, col);
 }
 
-static void tui_cursor_on(UI *ui)
+static void tui_busy_start(UI *ui)
 {
-  unibi_out(ui, unibi_cursor_normal);
+  ((TUIData *)ui->data)->busy = true;
 }
 
-static void tui_cursor_off(UI *ui)
+static void tui_busy_stop(UI *ui)
 {
-  unibi_out(ui, unibi_cursor_invisible);
+  ((TUIData *)ui->data)->busy = false;
 }
 
 static void tui_mouse_on(UI *ui)
@@ -527,6 +535,7 @@ static void tui_flush(UI *ui)
   }
 
   unibi_goto(ui, data->row, data->col);
+
   flush_buf(ui);
 }
 
@@ -657,7 +666,7 @@ static void out(void *ctx, const char *str, size_t len)
 {
   UI *ui = ctx;
   TUIData *data = ui->data;
-  size_t available = sizeof(data->buf) - data->bufpos;
+  size_t available = data->bufsize - data->bufpos;
 
   if (len > available) {
     flush_buf(ui);
@@ -781,14 +790,29 @@ end:
 
 static void flush_buf(UI *ui)
 {
-  static uv_write_t req;
-  static uv_buf_t buf;
+  uv_write_t req;
+  uv_buf_t buf;
   TUIData *data = ui->data;
+
+  if (!data->busy) {
+    // not busy and the cursor is invisible(see below). Append a "cursor
+    // normal" command to the end of the buffer.
+    data->bufsize += CNORM_COMMAND_MAX_SIZE;
+    unibi_out(ui, unibi_cursor_normal);
+    data->bufsize -= CNORM_COMMAND_MAX_SIZE;
+  }
+
   buf.base = data->buf;
   buf.len = data->bufpos;
   uv_write(&req, (uv_stream_t *)&data->output_handle, &buf, 1, NULL);
   uv_run(data->write_loop, UV_RUN_DEFAULT);
   data->bufpos = 0;
+
+  if (!data->busy) {
+    // not busy and cursor is visible(see above), append a "cursor invisible"
+    // command to the beginning of the buffer for the next flush
+    unibi_out(ui, unibi_cursor_invisible);
+  }
 }
 
 static void destroy_screen(TUIData *data)