Code displaying in submode line.

[flowchartsman]

I'm attempting to create a debugging submode for debugging scripts that ties in with VimDebug (http://vim.sourceforge.net/scripts/script.php?script_id=663). I've defined the first command in my .vimrc like so:

call submode#enter_with('Debug', 'n', '', 'D')

It seems to work, only when I hit 'D' from normal mode this is what I see on my status line:

-- Submode: Debug --                                                                   fix:Debug) 

Which I think is coming from submode.vim line 378? It doesn't matter what width my screen is, the same text is displayed on the right. If I change the definition to:

call submode#enter_with('DDDebug', 'n', '', 'D')

I get:

-- Submode: DDDebug --                                                                 x:DDDebug)

Which seems to indicate some sort of unintended echo problem.

[kana]

The strange characters are displayed by 'showcmd' option. If you type dat slowly, you'll see d and da at the bottom right corner. The same phenomenon happens in a submode.

Technically, submode consists of several combinations of key mappings. Suppose that we have the following definitions:

call submode#enter_with('undo/redo', 'n', '', 'g+', 'g+')
call submode#map('undo/redo', 'n', '', '+', 'g+')

These definitions are translated into the following plain key mappings:

" These are simplified for description.  Actual definitions are more complex.
nmap g+                                 g+<Plug>(submode-prefix:undo/redo)
nmap <Plug>(submode-prefix:undo/redo)+  g+<Plug>(submode-prefix:undo/redo)
nmap <Plug>(submode-prefix:undo/redo)   <Nop>

So that, when you are in a submode, Vim waits for more keys (after <Plug>(submode-prefix:...)) to determine a command to be executed.

If 'showcmd' is enabled, Vim shows typed-but-not-executed-as-a-command characters. In a submode, the characters are too many to show in the bottom right corner. So that Vim shows only the last few characters. Resulting screen is odd for users, as you described.

A quick fix is to turn off 'showcmd' in a submode. But it causes another problem about screen rendering. See gh-9.