vim-patch:9.1.0990: Inconsistent behavior when changing cmdheight (#31830)

Problem:  Inconsistent behavior when changing cmdheight by resizing the
          topframe through wincmds and dragging laststatus. Changing
          cmdheight by resizing the topframe does not trigger OptionSet.
Solution: Consolidate logic for changing the cmdheight, set the option
          value to handle side-effects (Luuk van Baal)

https://github.com/vim/vim/commit/e15cbc1af47e9dea90448c714eb4908e5d4302fc

vim-patch:9.0.0187: command line height changes when maximizing window height

Problem:  Command line height changes when maximizing window height.
Solution: Do not change the command line height. (closes vim/vim#10885)

https://github.com/vim/vim/commit/96bde99bf890acd9952863a02c1d15edca2000e1

6 files changed, 76 insertions, 6 deletions

diff --git a/test/functional/legacy/cmdline_spec.lua b/test/functional/legacy/cmdline_spec.lua
index 3addcb957c..22700990c1 100644
--- a/test/functional/legacy/cmdline_spec.lua
+++ b/test/functional/legacy/cmdline_spec.lua
@@ -159,6 +159,52 @@ describe('cmdline', function()
       endfunc
     ]])
 
+    feed(':resize -3<CR>')
+    screen:expect([[
+      ^                                                            |
+      {1:~                                                           }|*2
+      {3:[No Name]                                                   }|
+                                                                  |*4
+    ]])
+
+    -- :resize now also changes 'cmdheight' accordingly
+    feed(':set cmdheight+=1<CR>')
+    screen:expect([[
+      ^                                                            |
+      {1:~                                                           }|
+      {3:[No Name]                                                   }|
+                                                                  |*5
+    ]])
+    feed(':set cmdheight-=1<CR>')
+
+    -- using more space moves the status line up
+    feed(':set cmdheight+=1<CR>')
+    screen:expect([[
+      ^                                                            |
+      {1:~                                                           }|
+      {3:[No Name]                                                   }|
+                                                                  |*5
+    ]])
+
+    -- reducing cmdheight moves status line down
+    feed(':set cmdheight-=2<CR>')
+    screen:expect([[
+      ^                                                            |
+      {1:~                                                           }|*3
+      {3:[No Name]                                                   }|
+                                                                  |*3
+    ]])
+
+    -- reducing window size and then setting cmdheight
+    feed(':resize -1<CR>')
+    feed(':set cmdheight=1<CR>')
+    screen:expect([[
+      ^                                                            |
+      {1:~                                                           }|*5
+      {3:[No Name]                                                   }|
+                                                                  |
+    ]])
+
     -- setting 'cmdheight' works after outputting two messages
     feed(':call EchoTwo()')
     screen:expect([[
diff --git a/test/functional/legacy/messages_spec.lua b/test/functional/legacy/messages_spec.lua
index adf75c2836..db5e3f6857 100644
--- a/test/functional/legacy/messages_spec.lua
+++ b/test/functional/legacy/messages_spec.lua
@@ -82,7 +82,7 @@ describe('messages', function()
       NoSuchFil^e                                                  |
       three                                                       |
       {1:~                                                           }|*5
-      from DebugSilent visual                                     |
+                                                                  |
       {9:E447: Can't find file "NoSuchFile" in path}                  |
     ]])
   end)
diff --git a/test/functional/legacy/window_cmd_spec.lua b/test/functional/legacy/window_cmd_spec.lua
index b58bf0bf43..fac982354c 100644
--- a/test/functional/legacy/window_cmd_spec.lua
+++ b/test/functional/legacy/window_cmd_spec.lua
@@ -299,7 +299,7 @@ describe('splitkeep', function()
       c                                                    |
       {1:~                                                    }|
       {3:[No Name]                                            }|
-                                                           |
+      :call win_move_statusline(win, 1)                    |
     ]])
   end)
 
diff --git a/test/old/testdir/test_autocmd.vim b/test/old/testdir/test_autocmd.vim
index 40c09e61ac..d5f7c928de 100644
--- a/test/old/testdir/test_autocmd.vim
+++ b/test/old/testdir/test_autocmd.vim
@@ -4181,4 +4181,28 @@ func Test_autocmd_BufWinLeave_with_vsp()
   exe "bw! " .. dummy
 endfunc
 
+func Test_OptionSet_cmdheight()
+  set mouse=a laststatus=2
+  au OptionSet cmdheight :let &l:ch = v:option_new
+
+  resize -1
+  call assert_equal(2, &l:ch)
+  resize +1
+  call assert_equal(1, &l:ch)
+
+  call Ntest_setmouse(&lines - 1, 1)
+  call feedkeys("\<LeftMouse>", 'xt')
+  call Ntest_setmouse(&lines - 2, 1)
+  call feedkeys("\<LeftDrag>", 'xt')
+  call assert_equal(2, &l:ch)
+
+  tabnew | resize +1
+  call assert_equal(1, &l:ch)
+  tabfirst
+  call assert_equal(2, &l:ch)
+
+  tabonly
+  set cmdheight& mouse& laststatus&
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/test/old/testdir/test_cmdline.vim b/test/old/testdir/test_cmdline.vim
index cbce0e908d..3fce086040 100644
--- a/test/old/testdir/test_cmdline.vim
+++ b/test/old/testdir/test_cmdline.vim
@@ -291,9 +291,10 @@ func Test_changing_cmdheight()
   call term_sendkeys(buf, ":resize -3\<CR>")
   call VerifyScreenDump(buf, 'Test_changing_cmdheight_1', {})
 
-  " using the space available doesn't change the status line
-  call term_sendkeys(buf, ":set cmdheight+=3\<CR>")
+  " :resize now also changes 'cmdheight' accordingly
+  call term_sendkeys(buf, ":set cmdheight+=1\<CR>")
   call VerifyScreenDump(buf, 'Test_changing_cmdheight_2', {})
+  call term_sendkeys(buf, ":set cmdheight-=1\<CR>")
 
   " using more space moves the status line up
   call term_sendkeys(buf, ":set cmdheight+=1\<CR>")
@@ -312,7 +313,7 @@ func Test_changing_cmdheight()
   call term_sendkeys(buf, ":call EchoTwo()\<CR>")
   call VerifyScreenDump(buf, 'Test_changing_cmdheight_6', {})
 
-  " increasing 'cmdheight' doesn't clear the messages that need hit-enter
+  " decreasing 'cmdheight' doesn't clear the messages that need hit-enter
   call term_sendkeys(buf, ":call EchoOne()\<CR>")
   call VerifyScreenDump(buf, 'Test_changing_cmdheight_7', {})
 
diff --git a/test/old/testdir/test_window_cmd.vim b/test/old/testdir/test_window_cmd.vim
index 343bc9fd83..24517f90cb 100644
--- a/test/old/testdir/test_window_cmd.vim
+++ b/test/old/testdir/test_window_cmd.vim
@@ -56,7 +56,6 @@ func Test_window_cmd_cmdwin_with_vsp()
 endfunc
 
 func Test_cmdheight_not_changed()
-  throw 'Skipped: N/A'
   set cmdheight=2
   set winminheight=0
   augroup Maximize