fix(messages): verbose kind for nvim_echo()

Problem:  No "verbose" kind for nvim_echo() opts->verbose.
Solution: Pass NULL "kind" to indicate no new kind.

src/nvim/api/vim.c

@@ -772,7 +772,8 @@ void nvim_echo(Array chunks, Boolean history, Dict(echo_opts) *opts, Error *err)
     verbose_enter();
   }
 
-  msg_multihl(hl_msg, opts->err ? "echoerr" : history ? "echomsg" : "echo", history, opts->err);
+  char *kind = opts->verbose ? NULL : opts->err ? "echoerr" : history ? "echomsg" : "echo";
+  msg_multihl(hl_msg, kind, history, opts->err);
 
   if (opts->verbose) {
     verbose_leave();

src/nvim/message.c

@@ -296,6 +296,12 @@ void msg_multiline(String str, int hl_id, bool check_int, bool hist, bool *need_
 // Avoid starting a new message for each chunk and adding message to history in msg_keep().
 static bool is_multihl = false;
 
+/// Print message chunks, each with their own highlight ID.
+///
+/// @param hl_msg Message chunks
+/// @param kind Message kind (can be NULL to avoid setting kind)
+/// @param history Whether to add message to history
+/// @param err Whether to print message as an error
 void msg_multihl(HlMessage hl_msg, const char *kind, bool history, bool err)
 {
   no_wait_return++;
@@ -303,7 +309,9 @@ void msg_multihl(HlMessage hl_msg, const char *kind, bool history, bool err)
   msg_clr_eos();
   bool need_clear = false;
   msg_ext_history = history;
-  msg_ext_set_kind(kind);
+  if (kind != NULL) {
+    msg_ext_set_kind(kind);
+  }
   is_multihl = true;
   for (uint32_t i = 0; i < kv_size(hl_msg); i++) {
     HlMessageChunk chunk = kv_A(hl_msg, i);
@@ -312,7 +320,7 @@ void msg_multihl(HlMessage hl_msg, const char *kind, bool history, bool err)
     } else {
       msg_multiline(chunk.text, chunk.hl_id, true, false, &need_clear);
     }
-    assert(!ui_has(kUIMessages) || msg_ext_kind == kind);
+    assert(!ui_has(kUIMessages) || kind == NULL || msg_ext_kind == kind);
   }
   if (history && kv_size(hl_msg)) {
     add_msg_hist_multihl(NULL, 0, 0, true, hl_msg);

test/functional/ui/messages_spec.lua

@@ -319,9 +319,7 @@ describe('ui/ext_messages', function()
     -- kind=echoerr for nvim_echo() err
     feed(':call nvim_echo([["Error"], ["Message", "Special"]], 1, #{ err:1 })<CR>')
     screen:expect({
-      cmdline = { {
-        abort = false,
-      } },
+      cmdline = { { abort = false } },
       messages = {
         {
           content = { { 'Error', 9, 6 }, { 'Message', 16, 99 } },
@@ -331,12 +329,23 @@ describe('ui/ext_messages', function()
       },
     })
 
+    -- kind=verbose for nvim_echo() verbose
+    feed(':call nvim_echo([["Verbose Message"]], 1, #{ verbose:1 })<CR>')
+    screen:expect({
+      cmdline = { { abort = false } },
+      messages = {
+        {
+          content = { { 'Verbose Message' } },
+          history = true,
+          kind = 'verbose',
+        },
+      },
+    })
+
     -- kind=verbose for :verbose messages
     feed(':1verbose filter Diff[AC] hi<CR>')
     screen:expect({
-      cmdline = { {
-        abort = false,
-      } },
+      cmdline = { { abort = false } },
       messages = {
         {
           content = {
@@ -387,9 +396,7 @@ describe('ui/ext_messages', function()
       or '{ echo stdout; echo stderr >&2; exit 3; }'
     feed(('<CR>:!%s<CR>'):format(cmd))
     screen:expect({
-      cmdline = { {
-        abort = false,
-      } },
+      cmdline = { { abort = false } },
       messages = {
         {
           content = { { (':!%s\r\n[No write since last change]\n'):format(cmd) } },
@@ -1126,9 +1133,7 @@ describe('ui/ext_messages', function()
         ^                         |
         {1:~                        }|*4
       ]],
-      cmdline = { {
-        abort = false,
-      } },
+      cmdline = { { abort = false } },
     })
     eq(0, eval('&cmdheight'))
   end)