From 94ce25065bb709794904b8ee96c1144006520750 Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Mon, 26 Dec 2022 14:04:46 +0800
Subject: [PATCH] fix(showcmd): assert failure with cmdheight=0 (#21536)

---
 src/nvim/normal.c                   |  3 +++
 test/functional/ui/cmdline_spec.lua | 13 +++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index 1f7cc6c4f6..7979d2502e 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -1990,6 +1990,9 @@ static void display_showcmd(void)
     return;
   }
   // 'showcmdloc' is "last" or empty
+  if (p_ch == 0 && !ui_has(kUIMessages)) {
+    return;
+  }
 
   if (ui_has(kUIMessages)) {
     MAXSIZE_TEMP_ARRAY(content, 1);
diff --git a/test/functional/ui/cmdline_spec.lua b/test/functional/ui/cmdline_spec.lua
index c73c2d9f8a..1bdd55d66b 100644
--- a/test/functional/ui/cmdline_spec.lua
+++ b/test/functional/ui/cmdline_spec.lua
@@ -1351,4 +1351,17 @@ describe('cmdheight=0', function()
       {1:~                             }│{1:~                            }|
     ]])
   end)
+
+  it('no assert failure with showcmd', function()
+    command('set showcmd cmdheight=0')
+    feed('d')
+    screen:expect([[
+      ^                         |
+      {1:~                        }|
+      {1:~                        }|
+      {1:~                        }|
+      {1:~                        }|
+    ]])
+    assert_alive()
+  end)
 end)