fix(ruler): show ruler of curwin with no statusline in cmdline

Problem: After neovim/neovim@846a056, only the ruler for current floating or
last window without a statusline is drawn in the cmdline. This means that if the
current window is not one of these, but has no statusline, its ruler will not be
drawn anymore.

Solution: Make `showmode()` draw the ruler of the current window or the last
window in the cmdline if it has no statusline. This also maintains the
previously restored floating window case (`float->w_status_height` should be 0).

This behaviour should again match Vim, but without the overdraw it seems to do
to achieve the same effect; it calls `showmode()` to draw the ruler for the last
window without a statusline, then may draw over it in `showruler()` (which is
now `show_cursor_info_later()` in Nvim) to show the ruler for the current
window..? It's very confusing.

Also update the logic in `win_redr_ruler()` to mirror the check done in
`showmode()`, so that the ruler doesn't potentially draw over the long
ins-completion mode message in some cases.

1 files changed, 115 insertions, 0 deletions

diff --git a/test/functional/ui/float_spec.lua b/test/functional/ui/float_spec.lua
index 0e1842d087..e2fe0a2df5 100644
--- a/test/functional/ui/float_spec.lua
+++ b/test/functional/ui/float_spec.lua
@@ -2340,6 +2340,121 @@ describe('float window', function()
       end
     end)
 
+    it('does not show ruler of not-last current float during ins-completion', function()
+      screen:try_resize(50,9)
+      command 'set ruler showmode'
+      meths.open_win(0, false, {relative='editor', width=3, height=3, row=0, col=0})
+      meths.open_win(0, false, {relative='editor', width=3, height=3, row=0, col=5})
+      feed '<c-w>w'
+      neq('', meths.win_get_config(0).relative)
+      neq(funcs.winnr '$', funcs.winnr())
+      if multigrid then
+        screen:expect{grid=[[
+        ## grid 1
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [3:--------------------------------------------------]|
+        ## grid 2
+                                                            |
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+        ## grid 3
+                                          0,0-1         All |
+        ## grid 4
+          {1:   }|
+          {2:~  }|
+          {2:~  }|
+        ## grid 5
+          {1:^   }|
+          {2:~  }|
+          {2:~  }|
+        ]], float_pos={
+          [5] = {{id = 1002}, "NW", 1, 0, 5, true, 50};
+          [4] = {{id = 1001}, "NW", 1, 0, 0, true, 50};
+        }, win_viewport={
+          [2] = {win = {id = 1000}, topline = 0, botline = 2, curline = 0, curcol = 0, linecount = 1, sum_scroll_delta = 0};
+          [4] = {win = {id = 1001}, topline = 0, botline = 2, curline = 0, curcol = 0, linecount = 1, sum_scroll_delta = 0};
+          [5] = {win = {id = 1002}, topline = 0, botline = 2, curline = 0, curcol = 0, linecount = 1, sum_scroll_delta = 0};
+        }}
+      else
+        screen:expect{grid=[[
+          {1:   }  {1:^   }                                          |
+          {2:~  }{0:  }{2:~  }{0:                                          }|
+          {2:~  }{0:  }{2:~  }{0:                                          }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+                                          0,0-1         All |
+        ]]}
+      end
+      feed 'i<c-x>'
+      if multigrid then
+        screen:expect{grid=[[
+        ## grid 1
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [2:--------------------------------------------------]|
+          [3:--------------------------------------------------]|
+        ## grid 2
+                                                            |
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+        ## grid 3
+          {3:-- ^X mode (^]^D^E^F^I^K^L^N^O^Ps^U^V^Y)}          |
+        ## grid 4
+          {1:   }|
+          {2:~  }|
+          {2:~  }|
+        ## grid 5
+          {1:^   }|
+          {2:~  }|
+          {2:~  }|
+        ]], float_pos={
+          [5] = {{id = 1002}, "NW", 1, 0, 5, true, 50};
+          [4] = {{id = 1001}, "NW", 1, 0, 0, true, 50};
+        }, win_viewport={
+          [2] = {win = {id = 1000}, topline = 0, botline = 2, curline = 0, curcol = 0, linecount = 1, sum_scroll_delta = 0};
+          [4] = {win = {id = 1001}, topline = 0, botline = 2, curline = 0, curcol = 0, linecount = 1, sum_scroll_delta = 0};
+          [5] = {win = {id = 1002}, topline = 0, botline = 2, curline = 0, curcol = 0, linecount = 1, sum_scroll_delta = 0};
+        }}
+      else
+        screen:expect{grid=[[
+          {1:   }  {1:^   }                                          |
+          {2:~  }{0:  }{2:~  }{0:                                          }|
+          {2:~  }{0:  }{2:~  }{0:                                          }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {0:~                                                 }|
+          {3:-- ^X mode (^]^D^E^F^I^K^L^N^O^Ps^U^V^Y)}          |
+        ]]}
+      end
+    end)
+
     it('can have minimum size', function()
       insert("the background text")
       local buf = meths.create_buf(false, true)