vim-patch:8.2.3989: some insert completion code is not tested

Problem:    Some insert completion code is not tested.
Solution:   Add a few tests.  Refactor thesaurus completion. (Yegappan
            Lakshmanan, closes vim/vim#9460)
https://github.com/vim/vim/commit/e982586f8eebf2b055987218f6d3f7a084c4bf69

vim-patch:9.0.0254: typo in function name

Problem:    Typo in function name.
Solution:   Rename the function. (closes vim/vim#10971)
https://github.com/vim/vim/commit/5fb3aabc2b0edd5573e107bb3bc103c348771f61

2 files changed, 126 insertions, 2 deletions

diff --git a/src/nvim/testdir/test_edit.vim b/src/nvim/testdir/test_edit.vim
index fa288df0d9..679b877ef6 100644
--- a/src/nvim/testdir/test_edit.vim
+++ b/src/nvim/testdir/test_edit.vim
@@ -730,8 +730,13 @@ func Test_edit_CTRL_N()
     call feedkeys("Ii\<c-n>\<cr>\<esc>", "tnix")
     call feedkeys("ILO\<c-n>\<cr>\<esc>", 'tnix')
     call assert_equal(['INFER', 'loWER', 'infer', 'LOWER', '', ''], getline(1, '$'), e)
-
-    set noignorecase noinfercase complete&
+    set noignorecase noinfercase
+    %d
+    call setline(1, ['one word', 'two word'])
+    exe "normal! Goo\<C-P>\<C-X>\<C-P>"
+    call assert_equal('one word', getline(3))
+    %d
+    set complete&
     bw!
   endfor
 endfunc
@@ -897,6 +902,24 @@ func Test_edit_CTRL_T()
   bw!
 endfunc
 
+" Test thesaurus completion with different encodings
+func Test_thesaurus_complete_with_encoding()
+  call writefile(['angry furious mad enraged'], 'Xthesaurus')
+  set thesaurus=Xthesaurus
+  " for e in ['latin1', 'utf-8']
+  for e in ['utf-8']
+    exe 'set encoding=' .. e
+    new
+    call setline(1, 'mad')
+    call cursor(1, 1)
+    call feedkeys("A\<c-x>\<c-t>\<cr>\<esc>", 'tnix')
+    call assert_equal(['mad', ''], getline(1, '$'))
+    bw!
+  endfor
+  set thesaurus=
+  call delete('Xthesaurus')
+endfunc
+
 " Test 'thesaurusfunc'
 func MyThesaurus(findstart, base)
   let mythesaurus = [
diff --git a/src/nvim/testdir/test_ins_complete.vim b/src/nvim/testdir/test_ins_complete.vim
index 8f7d2cb278..914d818eef 100644
--- a/src/nvim/testdir/test_ins_complete.vim
+++ b/src/nvim/testdir/test_ins_complete.vim
@@ -682,6 +682,21 @@ func Test_complete_func_error()
   call assert_equal([], complete_info(['items']).items)
 endfunc
 
+" Test for recursively starting completion mode using complete()
+func Test_recursive_complete_func()
+  func ListColors()
+    call complete(5, ["red", "blue"])
+    return ''
+  endfunc
+  new
+  call setline(1, ['a1', 'a2'])
+  set complete=.
+  exe "normal Goa\<C-X>\<C-L>\<C-R>=ListColors()\<CR>\<C-N>"
+  call assert_equal('a2blue', getline(3))
+  delfunc ListColors
+  bw!
+endfunc
+
 " Test for completing words following a completed word in a line
 func Test_complete_wrapscan()
   " complete words from another buffer
@@ -905,6 +920,92 @@ func Test_issue_7021()
   set completeslash=
 endfunc
 
+" Test for 'longest' setting in 'completeopt' with latin1 and utf-8 encodings
+func Test_complete_longest_match()
+  " for e in ['latin1', 'utf-8']
+  for e in ['utf-8']
+    exe 'set encoding=' .. e
+    new
+    set complete=.
+    set completeopt=menu,longest
+    call setline(1, ['pfx_a1', 'pfx_a12', 'pfx_a123', 'pfx_b1'])
+    exe "normal Gopfx\<C-P>"
+    call assert_equal('pfx_', getline(5))
+    bw!
+  endfor
+
+  " Test for completing additional words with longest match set
+  new
+  call setline(1, ['abc1', 'abd2'])
+  exe "normal Goab\<C-P>\<C-X>\<C-P>"
+  call assert_equal('ab', getline(3))
+  bw!
+  set complete& completeopt&
+endfunc
+
+" Test for removing the first displayed completion match and selecting the
+" match just before that.
+func Test_complete_erase_firstmatch()
+  new
+  call setline(1, ['a12', 'a34', 'a56'])
+  set complete=.
+  exe "normal Goa\<C-P>\<BS>\<BS>3\<CR>"
+  call assert_equal('a34', getline('$'))
+  set complete&
+  bw!
+endfunc
+
+" Test for completing whole lines from unloaded buffers
+func Test_complete_wholeline_unloadedbuf()
+  call writefile(['a line1', 'a line2', 'a line3'], "Xfile1")
+  edit Xfile1
+  enew
+  set complete=u
+  exe "normal! ia\<C-X>\<C-L>\<C-P>"
+  call assert_equal('a line2', getline(1))
+  %d
+  " completing from an unlisted buffer should fail
+  bdel Xfile1
+  exe "normal! ia\<C-X>\<C-L>\<C-P>"
+  call assert_equal('a', getline(1))
+  set complete&
+  %bw!
+  call delete("Xfile1")
+endfunc
+
+" Test for completing whole lines from unlisted buffers
+func Test_complete_wholeline_unlistedbuf()
+  call writefile(['a line1', 'a line2', 'a line3'], "Xfile1")
+  edit Xfile1
+  enew
+  set complete=U
+  " completing from a unloaded buffer should fail
+  exe "normal! ia\<C-X>\<C-L>\<C-P>"
+  call assert_equal('a', getline(1))
+  %d
+  bdel Xfile1
+  exe "normal! ia\<C-X>\<C-L>\<C-P>"
+  call assert_equal('a line2', getline(1))
+  set complete&
+  %bw!
+  call delete("Xfile1")
+endfunc
+
+" Test for adding a multibyte character using CTRL-L in completion mode
+func Test_complete_mbyte_char_add()
+  new
+  set complete=.
+  call setline(1, 'abė')
+  exe "normal! oa\<C-P>\<BS>\<BS>\<C-L>\<C-L>"
+  call assert_equal('abė', getline(2))
+  " Test for a leader with multibyte character
+  %d
+  call setline(1, 'abėĕ')
+  exe "normal! oabė\<C-P>"
+  call assert_equal('abėĕ', getline(2))
+  bw!
+endfunc
+
 " Test to ensure 'Scanning...' messages are not recorded in messages history
 func Test_z1_complete_no_history()
   new