Disabling use of Tab to accept copilot suggestion causes Tab to insert the letter "t"

[mwagnell]

I found that if I disabled the use of tab to accept copilot suggestions as described in the help information, the Tab key would then insert the letter "t". I fixed that with the change below, but this seems like a basic enough problem that I'm wondering if there might be something more subtle going on.

diff --git i/plugin/copilot.vim w/plugin/copilot.vim
index 4d3d216..41ee457 100644
--- i/plugin/copilot.vim
+++ w/plugin/copilot.vim
@@ -26,7 +26,7 @@ function! s:MapTab() abort
   endif
   let tab_map = maparg('<Tab>', 'i', 0, 1)
   if !has_key(tab_map, 'rhs')
-    imap <script><silent><nowait><expr> <Tab> empty(get(g:, 'copilot_no_tab_map')) ? copilot#Accept() : "\t"
+    imap <script><silent><nowait><expr> <Tab> empty(get(g:, 'copilot_no_tab_map')) ? copilot#Accept() : "<Tab>"
   elseif tab_map.rhs !~# 'copilot'
     if tab_map.expr
       let tab_fallback = '{ -> ' . tab_map.rhs . ' }'

[tpope]

Check :verbose imap <Tab>. My guess would be that something else is altering the map after the fact.

[mwagnell]

The result of that (with copilot.vim reverted back to the original code):

i  <Tab>       & empty(get(g:, 'copilot_no_tab_map')) ? copilot#Accept() : "t"
        Last set from /path/obscured/.vim/pack/github/start/copilot.vim/plugin/copilot.vim line 30

This is with vim 9.1, including patches 1-836.

Seems to me that the right hand side of the mapping doesn't support using \t to represent a tab character. I wasn't able to clearly figure out whether vim should be doing that from the help.

I see now that if I let g:copilot_no_tab_map = v:true BEFORE packloadall, in my vimrc file, then the plugin never defines a mapping for at all. I'd suspect that is how it has been tested, and the usage of defining that AFTER doing the packloadall doesn't work. It's either that, or there's a bug in the version of vim I'm using.