From 8bdfd286e5846325bf51e12f116ec56d38eaa212 Mon Sep 17 00:00:00 2001
From: luukvbaal <luukvbaal@gmail.com>
Date: Mon, 19 Jan 2026 17:15:44 +0100
Subject: [PATCH] fix(messages): adjust msg_show "empty" kind logic (#37427)

Problem:  A message ending in an unprintable character may emit a
          msg_show event with the "empty" kind. No empty message event
          for echom "".
Solution: Adjust conditions for emitting "empty" msg_show events.
---
 src/nvim/message.c                   | 8 +++++---
 test/functional/ui/messages_spec.lua | 7 ++++---
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/nvim/message.c b/src/nvim/message.c
index 1ac260f670..fcf85a3c84 100644
--- a/src/nvim/message.c
+++ b/src/nvim/message.c
@@ -286,8 +286,10 @@ void msg_multiline(String str, int hl_id, bool check_int, bool hist, bool *need_
     s++;
   }
 
-  // Print the rest of the message
-  msg_outtrans_len(chunk, (int)(str.size - (size_t)(chunk - str.data)), hl_id, hist);
+  // Print the remainder or emit empty event if entire message is empty.
+  if (*chunk != NUL || chunk == str.data) {
+    msg_outtrans_len(chunk, (int)(str.size - (size_t)(chunk - str.data)), hl_id, hist);
+  }
 }
 
 // Avoid starting a new message for each chunk and adding message to history in msg_keep().
@@ -1748,7 +1750,7 @@ static void msg_home_replace_hl(const char *fname, int hl_id)
 /// @return  the number of characters it takes on the screen.
 int msg_outtrans(const char *str, int hl_id, bool hist)
 {
-  return *str == NUL ? 0 : msg_outtrans_len(str, (int)strlen(str), hl_id, hist);
+  return msg_outtrans_len(str, (int)strlen(str), hl_id, hist);
 }
 
 /// Output one character at "p".
diff --git a/test/functional/ui/messages_spec.lua b/test/functional/ui/messages_spec.lua
index 2fe75278b2..ec34ecf349 100644
--- a/test/functional/ui/messages_spec.lua
+++ b/test/functional/ui/messages_spec.lua
@@ -502,8 +502,8 @@ describe('ui/ext_messages', function()
       end,
     })
 
-    -- Empty messages
-    feed(':echo "foo" | echo "" | lua print()<CR>')
+    -- 3 empty message events, not for an empty chunk after a non-printable character
+    feed(':echo "foo\\n" | echo "" | echom "" | lua print()<CR>')
     screen:expect({
       grid = [[
         line 1                   |
@@ -511,7 +511,8 @@ describe('ui/ext_messages', function()
         {1:~                        }|*3
       ]],
       messages = {
-        { content = { { 'foo' } }, kind = 'echo' },
+        { content = { { 'foo\n' } }, kind = 'echo' },
+        { content = {}, kind = 'empty' },
         { content = {}, kind = 'empty' },
         { content = {}, kind = 'empty' },
       },