feat: cmdheight=0 #16251

Fix https://github.com/neovim/neovim/issues/1004

Limitation: All outputs need hit-enter prompt.

Related:
https://github.com/neovim/neovim/pull/6732
https://github.com/neovim/neovim/pull/4382

4 files changed, 160 insertions, 2 deletions

diff --git a/test/functional/options/num_options_spec.lua b/test/functional/options/num_options_spec.lua
index 4754c14f5b..f343e2da75 100644
--- a/test/functional/options/num_options_spec.lua
+++ b/test/functional/options/num_options_spec.lua
@@ -54,7 +54,7 @@ describe(':set validation', function()
     should_fail('iminsert', 3, 'E474')
     should_fail('imsearch', 3, 'E474')
     should_fail('titlelen', -1, 'E487')
-    should_fail('cmdheight', 0, 'E487')
+    should_fail('cmdheight', -1, 'E487')
     should_fail('updatecount', -1, 'E487')
     should_fail('textwidth', -1, 'E487')
     should_fail('tabstop', 0, 'E487')
diff --git a/test/functional/ui/cmdline_spec.lua b/test/functional/ui/cmdline_spec.lua
index 3b273fd229..0aee34d367 100644
--- a/test/functional/ui/cmdline_spec.lua
+++ b/test/functional/ui/cmdline_spec.lua
@@ -5,6 +5,8 @@ local source = helpers.source
 local command = helpers.command
 local assert_alive = helpers.assert_alive
 local uname = helpers.uname
+local eval = helpers.eval
+local eq = helpers.eq
 
 local function new_screen(opt)
   local screen = Screen.new(25, 5)
@@ -858,3 +860,156 @@ describe("cmdline height", function()
     assert_alive()
   end)
 end)
+
+describe('cmdheight=0', function()
+  local screen
+  before_each(function()
+    clear()
+    screen = Screen.new(25, 5)
+    screen:attach()
+  end)
+
+  it("with cmdheight=1 noruler laststatus=2", function()
+    command("set cmdheight=1 noruler laststatus=2")
+    screen:expect{grid=[[
+      ^                         |
+      ~                        |
+      ~                        |
+      [No Name]                |
+                               |
+    ]]}
+  end)
+
+  it("with cmdheight=0 noruler laststatus=2", function()
+    command("set cmdheight=0 noruler laststatus=2")
+    screen:expect{grid=[[
+      ^                         |
+      ~                        |
+      ~                        |
+      ~                        |
+      [No Name]                |
+    ]]}
+  end)
+
+  it("with cmdheight=0 ruler laststatus=0", function()
+    command("set cmdheight=0 ruler laststatus=0")
+    screen:expect{grid=[[
+      ^                         |
+      ~                        |
+      ~                        |
+      ~                        |
+      ~                        |
+    ]]}
+  end)
+
+  it("with cmdheight=0 ruler laststatus=0", function()
+    command("set cmdheight=0 noruler laststatus=0 showmode")
+    feed('i')
+    screen:expect{grid=[[
+      ^                         |
+      ~                        |
+      ~                        |
+      ~                        |
+      ~                        |
+    ]], showmode={}}
+    feed('<Esc>')
+    eq(0, eval('&cmdheight'))
+  end)
+
+  it("with showmode", function()
+    command("set cmdheight=1 noruler laststatus=0 showmode")
+    feed('i')
+    screen:expect{grid=[[
+      ^                         |
+      ~                        |
+      ~                        |
+      ~                        |
+      -- INSERT --             |
+    ]]}
+    feed('<Esc>')
+    eq(1, eval('&cmdheight'))
+  end)
+
+  it("when using command line", function()
+    command("set cmdheight=0 noruler laststatus=0")
+    feed(':')
+    screen:expect{grid=[[
+                               |
+      ~                        |
+      ~                        |
+      ~                        |
+      :^                        |
+    ]]}
+    eq(1, eval('&cmdheight'))
+    feed('<cr>')
+    screen:expect{grid=[[
+      ^                         |
+      ~                        |
+      ~                        |
+      ~                        |
+      ~                        |
+    ]], showmode={}}
+    eq(0, eval('&cmdheight'))
+  end)
+
+  it("when using input()", function()
+    command("set cmdheight=0 noruler laststatus=0")
+    feed(':call input("foo >")<cr>')
+    screen:expect{grid=[[
+                               |
+      ~                        |
+      ~                        |
+      ~                        |
+      foo >^                    |
+    ]]}
+    eq(1, eval('&cmdheight'))
+    feed('<cr>')
+    screen:expect{grid=[[
+      ^                         |
+      ~                        |
+      ~                        |
+      ~                        |
+      ~                        |
+    ]], showmode={}}
+    eq(0, eval('&cmdheight'))
+  end)
+
+  it("with winbar and splits", function()
+    command("set cmdheight=0 noruler laststatus=3 winbar=foo")
+    feed(':split<CR>')
+    screen:expect{grid=[[
+      foo                      |
+                               |
+      E36: Not enough room     |
+      Press ENTER or type comma|
+      nd to continue^           |
+    ]]}
+    feed('<CR>')
+    screen:expect{grid=[[
+      foo                      |
+      ^                         |
+      ~                        |
+      ~                        |
+      [No Name]                |
+    ]]}
+    feed(':')
+    screen:expect{grid=[[
+      foo                      |
+                               |
+      ~                        |
+      [No Name]                |
+      :^                        |
+    ]]}
+    feed('<Esc>')
+    screen:expect{grid=[[
+      foo                      |
+      ^                         |
+      ~                        |
+      ~                        |
+      [No Name]                |
+    ]], showmode={}}
+    eq(0, eval('&cmdheight'))
+
+    assert_alive()
+  end)
+end)
diff --git a/test/functional/ui/messages_spec.lua b/test/functional/ui/messages_spec.lua
index 7c789a9e58..e9c0e1b2a1 100644
--- a/test/functional/ui/messages_spec.lua
+++ b/test/functional/ui/messages_spec.lua
@@ -737,7 +737,6 @@ describe('ui/ext_messages', function()
     ]])
     eq(0, eval('&cmdheight'))
 
-    -- normally this would be an error
     feed(':set cmdheight=0')
     screen:expect{grid=[[
       ^                         |
diff --git a/test/functional/ui/statusline_spec.lua b/test/functional/ui/statusline_spec.lua
index 3e1b284856..2733b9dd4a 100644
--- a/test/functional/ui/statusline_spec.lua
+++ b/test/functional/ui/statusline_spec.lua
@@ -313,5 +313,9 @@ describe('global statusline', function()
     eq(2, meths.get_option('cmdheight'))
     meths.input_mouse('left', 'drag', '', 0, 14, 10)
     eq(1, meths.get_option('cmdheight'))
+    meths.input_mouse('left', 'drag', '', 0, 15, 10)
+    eq(0, meths.get_option('cmdheight'))
+    meths.input_mouse('left', 'drag', '', 0, 14, 10)
+    eq(1, meths.get_option('cmdheight'))
   end)
 end)