fix(messages): "list_cmd" kind for :command, :version (#34529)

Problem:  No ext_messages kind for the :command, :version commands.
          :version is emitted as multiple events.
Solution: Assign them the "list_cmd" kind. Use `msg_put*` to properly
          format the message as a single event.

src/nvim/usercmd.c

@@ -448,6 +448,7 @@ static void uc_list(char *name, size_t name_len)
 {
   bool found = false;
 
+  msg_ext_set_kind("list_cmd");
   // In cmdwin, the alternative buffer should be used.
   const garray_T *gap = &prevwin_curwin()->w_buffer->b_ucmds;
   while (true) {

src/nvim/version.c

@@ -2557,7 +2557,9 @@ void ex_version(exarg_T *eap)
 {
   // Ignore a ":version 9.99" command.
   if (*eap->arg == NUL) {
-    msg_putchar('\n');
+    if (!ui_has(kUIMessages)) {
+      msg_putchar('\n');
+    }
     list_version();
   }
 }
@@ -2671,19 +2673,23 @@ void list_lua_version(void)
                                 (Array)ARRAY_DICT_INIT, kRetObject, NULL, &err);
   assert(!ERROR_SET(&err));
   assert(ret.type == kObjectTypeString);
-  msg(ret.data.string.data, 0);
+  msg_puts(ret.data.string.data);
   api_free_object(ret);
 }
 
 void list_version(void)
 {
-  msg(longVersion, 0);
-  msg(version_buildtype, 0);
+  msg_ext_set_kind("list_cmd");
+  msg_puts(longVersion);
+  msg_putchar('\n');
+  msg_puts(version_buildtype);
+  msg_putchar('\n');
   list_lua_version();
 
   if (p_verbose > 0) {
 #ifndef NDEBUG
-    msg(version_cflags, 0);
+    msg_putchar('\n');
+    msg_puts(version_cflags);
 #endif
     version_msg("\n\n");
 

test/functional/ui/messages_spec.lua

@@ -534,6 +534,42 @@ describe('ui/ext_messages', function()
         },
       },
     })
+
+    command('command Foo Bar')
+    feed(':command<CR>')
+    screen:expect({
+      grid = [[
+        line 1                   |
+        ^line                     |
+        {1:~                        }|*3
+      ]],
+      cmdline = { { abort = false } },
+      messages = {
+        {
+          content = {
+            { '\n    Name              Args Address Complete    Definition', 101, 23 },
+            { '\n    ' },
+            { 'Foo', 18, 5 },
+            { '               0                        Bar' },
+          },
+          kind = 'list_cmd',
+        },
+      },
+    })
+
+    feed(':version<CR>')
+    screen:expect({
+      grid = [[
+        line 1                   |
+        ^line                     |
+        {1:~                        }|*3
+      ]],
+      cmdline = { { abort = false } },
+      condition = function()
+        eq('list_cmd', screen.messages[1].kind)
+        screen.messages = {}
+      end,
+    })
   end)
 
   it(':echoerr', function()

test/old/testdir/test_version.vim

@@ -9,7 +9,7 @@ func Test_version()
   let v2 = execute('version')
   call assert_equal(v1, v2)
 
-  call assert_match("^\n\nNVIM v[0-9]\\+\\.[0-9]\\+\\.[0-9]\\+.*", v1)
+  call assert_match("^\nNVIM v[0-9]\\+\\.[0-9]\\+\\.[0-9]\\+.*", v1)
 endfunc
 
 func Test_version_redirect()