feat(api): more fields in nvim_list_uis

Problem:
nvim_list_uis does not report all ":help ui-option" fields.

Solution:
Store ":help ui-option" fields on the `UI` object and update ui_array.

src/nvim/api/ui.c

@@ -113,6 +113,10 @@ void remote_ui_disconnect(uint64_t channel_id)
   kv_destroy(data->call_buf);
   pmap_del(uint64_t)(&connected_uis, channel_id);
   ui_detach_impl(ui, channel_id);
+
+  // Destroy `ui`.
+  XFREE_CLEAR(ui->term_name);
+  XFREE_CLEAR(ui->term_background);
   xfree(ui);
 }
 
@@ -163,15 +167,9 @@ void nvim_ui_attach(uint64_t channel_id, Integer width, Integer height, Dictiona
   UI *ui = xcalloc(1, sizeof(UI));
   ui->width = (int)width;
   ui->height = (int)height;
-  ui->pum_nlines = 0;
-  ui->pum_pos = false;
-  ui->pum_width = 0.0;
-  ui->pum_height = 0.0;
   ui->pum_row = -1.0;
   ui->pum_col = -1.0;
   ui->rgb = true;
-  ui->override = false;
-
   CLEAR_FIELD(ui->ui_ext);
 
   for (size_t i = 0; i < options.size; i++) {
@@ -320,6 +318,7 @@ static void ui_set_option(UI *ui, bool init, String name, Object value, Error *e
       return;
     });
     set_tty_option("term", string_to_cstr(value.data.string));
+    ui->term_name = string_to_cstr(value.data.string);
     return;
   }
 
@@ -328,6 +327,7 @@ static void ui_set_option(UI *ui, bool init, String name, Object value, Error *e
       return;
     });
     t_colors = (int)value.data.integer;
+    ui->term_colors = (int)value.data.integer;
     return;
   }
 
@@ -336,6 +336,7 @@ static void ui_set_option(UI *ui, bool init, String name, Object value, Error *e
       return;
     });
     set_tty_background(value.data.string.data);
+    ui->term_background = string_to_cstr(value.data.string);
     return;
   }
 
@@ -351,6 +352,7 @@ static void ui_set_option(UI *ui, bool init, String name, Object value, Error *e
     });
 
     stdin_fd = (int)value.data.integer;
+    ui->stdin_fd = (int)value.data.integer;
     return;
   }
 
@@ -359,6 +361,7 @@ static void ui_set_option(UI *ui, bool init, String name, Object value, Error *e
       return;
     });
     stdin_isatty = value.data.boolean;
+    ui->stdin_tty = value.data.boolean;
     return;
   }
 
@@ -367,6 +370,7 @@ static void ui_set_option(UI *ui, bool init, String name, Object value, Error *e
       return;
     });
     stdout_isatty = value.data.boolean;
+    ui->stdout_tty = value.data.boolean;
     return;
   }
 

src/nvim/ui.c

@@ -598,6 +598,15 @@ Array ui_array(void)
     PUT(info, "height", INTEGER_OBJ(ui->height));
     PUT(info, "rgb", BOOLEAN_OBJ(ui->rgb));
     PUT(info, "override", BOOLEAN_OBJ(ui->override));
+
+    // TUI fields.
+    PUT(info, "term_name", STRING_OBJ(cstr_to_string(ui->term_name)));
+    PUT(info, "term_background", STRING_OBJ(cstr_to_string(ui->term_background)));
+    PUT(info, "term_colors", INTEGER_OBJ(ui->term_colors));
+    PUT(info, "stdin_fd", INTEGER_OBJ(ui->stdin_fd));
+    PUT(info, "stdin_tty", BOOLEAN_OBJ(ui->stdin_tty));
+    PUT(info, "stdout_tty", BOOLEAN_OBJ(ui->stdout_tty));
+
     for (UIExtension j = 0; j < kUIExtCount; j++) {
       if (ui_ext_names[j][0] != '_' || ui->ui_ext[j]) {
         PUT(info, ui_ext_names[j], BOOLEAN_OBJ(ui->ui_ext[j]));

src/nvim/ui.h

@@ -103,6 +103,14 @@ struct ui_t {
   double pum_height;
   double pum_width;
 
+  // TUI fields.
+  char *term_name;
+  char *term_background;
+  int term_colors;
+  int stdin_fd;
+  bool stdin_tty;
+  bool stdout_tty;
+
   // TODO(bfredl): integrate into struct!
   UIData data[1];
 };

src/nvim/ui_client.c

@@ -1,6 +1,8 @@
 // This is an open source non-commercial project. Dear PVS-Studio, please check
 // it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
 
+/// Nvim's own UI client, which attaches to a child or remote Nvim server.
+
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>