'guicursor': enabled=false if 'guicursor' is empty

Closes #6429
Closes #6430

8 files changed, 49 insertions, 42 deletions

diff --git a/src/nvim/api/ui.c b/src/nvim/api/ui.c
index a95be0fabb..de60339e5f 100644
--- a/src/nvim/api/ui.c
+++ b/src/nvim/api/ui.c
@@ -300,11 +300,11 @@ static void remote_ui_scroll(UI *ui, int count)
   push_call(ui, "scroll", args);
 }
 
-static void remote_ui_cursor_style_set(UI *ui, Dictionary styles)
+static void remote_ui_cursor_style_set(UI *ui, bool enabled, Dictionary data)
 {
   Array args = ARRAY_DICT_INIT;
-  Object copy = copy_object(DICTIONARY_OBJ(styles));
-  ADD(args, copy);
+  ADD(args, BOOLEAN_OBJ(enabled));
+  ADD(args, copy_object(DICTIONARY_OBJ(data)));
   push_call(ui, "cursor_style_set", args);
 }
 
diff --git a/src/nvim/cursor_shape.c b/src/nvim/cursor_shape.c
index 7ec70bb724..34ee53bf75 100644
--- a/src/nvim/cursor_shape.c
+++ b/src/nvim/cursor_shape.c
@@ -89,10 +89,8 @@ char_u *parse_shape_opt(int what)
   int found_ve = false;                 /* found "ve" flag */
   int round;
 
-  /*
-   * First round: check for errors; second round: do it for real.
-   */
-  for (round = 1; round <= 2; ++round) {
+  // First round: check for errors; second round: do it for real.
+  for (round = 1; round <= 2; round++) {
     // Repeat for all comma separated parts.
     modep = p_guicursor;
     if (*p_guicursor == NUL) {
diff --git a/src/nvim/tui/tui.c b/src/nvim/tui/tui.c
index badc0cd870..f34f5f1bc4 100644
--- a/src/nvim/tui/tui.c
+++ b/src/nvim/tui/tui.c
@@ -84,6 +84,7 @@ typedef struct {
 } TUIData;
 
 static bool volatile got_winch = false;
+static bool cursor_style_enabled = false;
 
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "tui/tui.c.generated.h"
@@ -151,6 +152,7 @@ static void terminfo_start(UI *ui)
   // Set 't_Co' from the result of unibilium & fix_terminfo.
   t_colors = unibi_get_num(data->ut, unibi_max_colors);
   // Enter alternate screen and clear
+  // NOTE: Do this *before* changing terminal settings. #6433
   unibi_out(ui, unibi_enter_ca_mode);
   unibi_out(ui, unibi_clear_screen);
   // Enable bracketed paste
@@ -437,11 +439,11 @@ static void tui_cursor_goto(UI *ui, int row, int col)
 CursorShape tui_cursor_decode_shape(const char *shape_str)
 {
   CursorShape shape = 0;
-  if (strcmp(shape_str, "block") == 0) {
+  if (strequal(shape_str, "block")) {
     shape = SHAPE_BLOCK;
-  } else if (strcmp(shape_str, "vertical") == 0) {
+  } else if (strequal(shape_str, "vertical")) {
     shape = SHAPE_VER;
-  } else if (strcmp(shape_str, "horizontal") == 0) {
+  } else if (strequal(shape_str, "horizontal")) {
     shape = SHAPE_HOR;
   } else {
     EMSG2(_(e_invarg2), shape_str);
@@ -454,40 +456,41 @@ static cursorentry_T decode_cursor_entry(Dictionary args)
   cursorentry_T r;
 
   for (size_t i = 0; i < args.size; i++) {
-    char *keyStr = args.items[i].key.data;
+    char *key = args.items[i].key.data;
     Object value = args.items[i].value;
 
-    if (strcmp(keyStr, "cursor_shape") == 0) {
+    if (strequal(key, "cursor_shape")) {
       r.shape = tui_cursor_decode_shape(args.items[i].value.data.string.data);
-    } else if (strcmp(keyStr, "blinkon") == 0) {
+    } else if (strequal(key, "blinkon")) {
       r.blinkon = (int)value.data.integer;
-    } else if (strcmp(keyStr, "blinkoff") == 0) {
+    } else if (strequal(key, "blinkoff")) {
       r.blinkoff = (int)value.data.integer;
-    } else if (strcmp(keyStr, "hl_id") == 0) {
+    } else if (strequal(key, "hl_id")) {
       r.id = (int)value.data.integer;
     }
   }
   return r;
 }
 
-static void tui_cursor_style_set(UI *ui, Dictionary args)
+static void tui_cursor_style_set(UI *ui, bool enabled, Dictionary args)
 {
+  cursor_style_enabled = enabled;
+  if (!enabled) {
+    return;  // Do not send cursor style control codes.
+  }
   TUIData *data = ui->data;
 
+  assert(args.size);
+  // Keys: as defined by `shape_table`.
   for (size_t i = 0; i < args.size; i++) {
     char *mode_name = args.items[i].key.data;
     const int mode_id = cursor_mode_str2int(mode_name);
-
-    if (mode_id < 0) {
-      WLOG("Unknown mode '%s'", mode_name);
-      continue;
-    }
+    assert(mode_id >= 0);
     cursorentry_T r = decode_cursor_entry(args.items[i].value.data.dictionary);
     r.full_name = mode_name;
     data->cursor_shapes[mode_id] = r;
   }
 
-  // force redraw
   MouseMode cursor_mode = tui_mode2cursor(data->showing_mode);
   tui_set_cursor(ui, cursor_mode);
 }
@@ -528,6 +531,9 @@ static void tui_mouse_off(UI *ui)
 /// @param mode one of SHAPE_XXX
 static void tui_set_cursor(UI *ui, MouseMode mode)
 {
+  if (!cursor_style_enabled) {
+    return;
+  }
   TUIData *data = ui->data;
   cursorentry_T c = data->cursor_shapes[mode];
   int shape = c.shape;
@@ -536,17 +542,15 @@ static void tui_set_cursor(UI *ui, MouseMode mode)
 
 # define TMUX_WRAP(seq) (inside_tmux ? "\x1bPtmux;\x1b" seq "\x1b\\" : seq)
   // Support changing cursor shape on some popular terminals.
-  const char *term_prog = os_getenv("TERM_PROGRAM");
   const char *vte_version = os_getenv("VTE_VERSION");
 
-  if ((term_prog && !strcmp(term_prog, "Konsole"))
-      || os_getenv("KONSOLE_DBUS_SESSION") != NULL) {
+  if (os_getenv("KONSOLE_PROFILE_NAME") || os_getenv("KONSOLE_DBUS_SESSION")) {
     // Konsole uses a proprietary escape code to set the cursor shape
     // and does not support DECSCUSR.
     switch (shape) {
       case SHAPE_BLOCK: shape = 0; break;
       case SHAPE_VER:   shape = 1; break;
-      case SHAPE_HOR:   shape = 3; break;
+      case SHAPE_HOR:   shape = 2; break;
       default: WLOG("Unknown shape value %d", shape); break;
     }
     data->params[0].i = shape;
@@ -1102,15 +1106,15 @@ static const char *tui_tk_ti_getstr(const char *name, const char *value,
     stty_erase = tui_get_stty_erase();
   }
 
-  if (strcmp(name, "key_backspace") == 0) {
+  if (strequal(name, "key_backspace")) {
     ILOG("libtermkey:kbs=%s", value);
     if (stty_erase != NULL && stty_erase[0] != 0) {
       return stty_erase;
     }
-  } else if (strcmp(name, "key_dc") == 0) {
+  } else if (strequal(name, "key_dc")) {
     ILOG("libtermkey:kdch1=%s", value);
     // Vim: "If <BS> and <DEL> are now the same, redefine <DEL>."
-    if (stty_erase != NULL && value != NULL && strcmp(stty_erase, value) == 0) {
+    if (stty_erase != NULL && value != NULL && strequal(stty_erase, value)) {
       return stty_erase[0] == DEL ? CTRL_H_STR : DEL_STR;
     }
   }
diff --git a/src/nvim/ui.c b/src/nvim/ui.c
index babb4efa96..28f71b7ef2 100644
--- a/src/nvim/ui.c
+++ b/src/nvim/ui.c
@@ -381,7 +381,8 @@ void ui_cursor_goto(int new_row, int new_col)
 void ui_cursor_style_set(void)
 {
   Dictionary style = cursor_shape_dict();
-  UI_CALL(cursor_style_set, style);
+  bool enabled = (*p_guicursor != NUL);
+  UI_CALL(cursor_style_set, enabled, style);
   api_free_dictionary(style);
 }
 
diff --git a/src/nvim/ui.h b/src/nvim/ui.h
index 0af0c0db65..8ffc5a45a6 100644
--- a/src/nvim/ui.h
+++ b/src/nvim/ui.h
@@ -22,7 +22,7 @@ struct ui_t {
   void (*clear)(UI *ui);
   void (*eol_clear)(UI *ui);
   void (*cursor_goto)(UI *ui, int row, int col);
-  void (*cursor_style_set)(UI *ui, Dictionary cursor_shapes);
+  void (*cursor_style_set)(UI *ui, bool enabled, Dictionary cursor_styles);
   void (*update_menu)(UI *ui);
   void (*busy_start)(UI *ui);
   void (*busy_stop)(UI *ui);
diff --git a/src/nvim/ui_bridge.c b/src/nvim/ui_bridge.c
index c9bad6b254..9f780663ac 100644
--- a/src/nvim/ui_bridge.c
+++ b/src/nvim/ui_bridge.c
@@ -60,7 +60,7 @@ UI *ui_bridge_attach(UI *ui, ui_main_fn ui_main, event_scheduler scheduler)
   rv->bridge.clear = ui_bridge_clear;
   rv->bridge.eol_clear = ui_bridge_eol_clear;
   rv->bridge.cursor_goto = ui_bridge_cursor_goto;
-  rv->bridge.cursor_style_set = ui_bridge_cursor_styleset;
+  rv->bridge.cursor_style_set = ui_bridge_cursor_style_set;
   rv->bridge.update_menu = ui_bridge_update_menu;
   rv->bridge.busy_start = ui_bridge_busy_start;
   rv->bridge.busy_stop = ui_bridge_busy_stop;
@@ -180,19 +180,21 @@ static void ui_bridge_cursor_goto_event(void **argv)
   ui->cursor_goto(ui, PTR2INT(argv[1]), PTR2INT(argv[2]));
 }
 
-static void ui_bridge_cursor_styleset(UI *b, Dictionary style)
+static void ui_bridge_cursor_style_set(UI *b, bool enabled, Dictionary styles)
 {
-  Object copy = copy_object(DICTIONARY_OBJ(style));
-  Object *pobj = xmalloc(sizeof(copy));
-  *pobj = copy;
-  UI_CALL(b, cursor_styleset, 2, b, pobj);
+  bool *enabledp = xmalloc(sizeof(*enabledp));
+  Object *stylesp = xmalloc(sizeof(*stylesp));
+  *enabledp = enabled;
+  *stylesp = copy_object(DICTIONARY_OBJ(styles));
+  UI_CALL(b, cursor_style_set, 3, b, enabledp, stylesp);
 }
-static void ui_bridge_cursor_styleset_event(void **argv)
+static void ui_bridge_cursor_style_set_event(void **argv)
 {
   UI *ui = UI(argv[0]);
-  Object *styles = (Object *)argv[1];
-
-  ui->cursor_style_set(ui, styles->data.dictionary);
+  bool *enabled = argv[1];
+  Object *styles = argv[2];
+  ui->cursor_style_set(ui, *enabled, styles->data.dictionary);
+  xfree(enabled);
   api_free_object(*styles);
   xfree(styles);
 }
diff --git a/test/functional/ui/cursor_spec.lua b/test/functional/ui/cursor_spec.lua
index 1e3a9fcb60..c022a5649e 100644
--- a/test/functional/ui/cursor_spec.lua
+++ b/test/functional/ui/cursor_spec.lua
@@ -144,6 +144,7 @@ describe('ui/cursor', function()
       }
     -- Default 'guicursor' published on startup.
     eq(expected_cursor_style, screen._cursor_style)
+    eq(true, screen._cursor_style_enabled)
     eq('normal', screen.mode)
 
     -- Event is published ONLY if the cursor style changed.
diff --git a/test/functional/ui/screen.lua b/test/functional/ui/screen.lua
index 3f8173c8e2..ff71194dab 100644
--- a/test/functional/ui/screen.lua
+++ b/test/functional/ui/screen.lua
@@ -345,7 +345,8 @@ function Screen:_handle_resize(width, height)
   }
 end
 
-function Screen:_handle_cursor_style_set(style)
+function Screen:_handle_cursor_style_set(enabled, style)
+  self._cursor_style_enabled = enabled
   self._cursor_style = style
 end