vim-patch:9.1.0598: fuzzy completion does not work with default completion

Problem:  fuzzy completion does not work with default completion
Solution: Make it work (glepnir)

closes: vim/vim#15193

https://github.com/vim/vim/commit/8159fb18a92e9a9f5e35201bd92bf651f4d5835c

Cherry-pick insexpand.c changes from patch 9.1.0608.

N/A patch:
vim-patch:9.1.0632: MS-Windows: Compiler Warnings

Co-authored-by: glepnir <glephunter@gmail.com>

2 files changed, 67 insertions, 4 deletions

diff --git a/test/functional/ui/popupmenu_spec.lua b/test/functional/ui/popupmenu_spec.lua
index 728f8ed3d0..e41df13088 100644
--- a/test/functional/ui/popupmenu_spec.lua
+++ b/test/functional/ui/popupmenu_spec.lua
@@ -6938,9 +6938,9 @@ describe('builtin popupmenu', function()
         feed('S hello helio hero h<C-X><C-P>')
         screen:expect([[
            hello helio hero h^             |
-          {1:~                }{n: }{mn:h}{n:ello        }{1: }|
+          {1:~                }{n: }{mn:h}{n:ero         }{1: }|
           {1:~                }{n: }{mn:h}{n:elio        }{1: }|
-          {1:~                }{s: }{ms:h}{s:ero         }{1: }|
+          {1:~                }{s: }{ms:h}{s:ello        }{1: }|
           {1:~                               }|*15
           {2:-- }{5:match 1 of 3}                 |
         ]])
@@ -6948,9 +6948,9 @@ describe('builtin popupmenu', function()
         feed('<Esc>S hello helio hero h<C-X><C-P><C-P>')
         screen:expect([[
            hello helio hero h^             |
-          {1:~                }{n: }{mn:h}{n:ello        }{1: }|
-          {1:~                }{s: }{ms:h}{s:elio        }{1: }|
           {1:~                }{n: }{mn:h}{n:ero         }{1: }|
+          {1:~                }{s: }{ms:h}{s:elio        }{1: }|
+          {1:~                }{n: }{mn:h}{n:ello        }{1: }|
           {1:~                               }|*15
           {2:-- }{5:match 2 of 3}                 |
         ]])
diff --git a/test/old/testdir/test_ins_complete.vim b/test/old/testdir/test_ins_complete.vim
index a08d0bd252..9b123a65b6 100644
--- a/test/old/testdir/test_ins_complete.vim
+++ b/test/old/testdir/test_ins_complete.vim
@@ -2832,6 +2832,68 @@ func Test_complete_fuzzy_match()
   call feedkeys("A\<C-X>\<C-N>\<Esc>0", 'tx!')
   call assert_equal('hello help hero h', getline('.'))
 
+  set completeopt-=noinsert
+  call setline(1, ['xyz  yxz  x'])
+  call feedkeys("A\<C-X>\<C-N>\<Esc>0", 'tx!')
+  call assert_equal('xyz  yxz  xyz', getline('.'))
+  " can fuzzy get yxz when use Ctrl-N twice
+  call setline(1, ['xyz  yxz  x'])
+  call feedkeys("A\<C-X>\<C-N>\<C-N>\<Esc>0", 'tx!')
+  call assert_equal('xyz  yxz  yxz', getline('.'))
+
+  call setline(1, ['你好 你'])
+  call feedkeys("A\<C-X>\<C-N>\<Esc>0", 'tx!')
+  call assert_equal('你好 你好', getline('.'))
+  call setline(1, ['你的 我的 的'])
+  call feedkeys("A\<C-X>\<C-N>\<Esc>0", 'tx!')
+  call assert_equal('你的 我的 你的', getline('.'))
+  " can fuzzy get multiple-byte word when use Ctrl-N twice
+  call setline(1, ['你的 我的 的'])
+  call feedkeys("A\<C-X>\<C-N>\<C-N>\<Esc>0", 'tx!')
+  call assert_equal('你的 我的 我的', getline('.'))
+
+  " respect wrapscan
+  set nowrapscan
+  call setline(1, ["xyz", "yxz", ""])
+  call cursor(3, 1)
+  call feedkeys("Sy\<C-X>\<C-N>\<Esc>0", 'tx!')
+  call assert_equal('y', getline('.'))
+  set wrapscan
+  call feedkeys("Sy\<C-X>\<C-N>\<Esc>0", 'tx!')
+  call assert_equal('xyz', getline('.'))
+
+  " fuzzy on file
+  call writefile([''], 'fobar', 'D')
+  call writefile([''], 'foobar', 'D')
+  call setline(1, ['fob'])
+  call cursor(1, 1)
+  call feedkeys("A\<C-X>\<C-f>\<Esc>0", 'tx!')
+  call assert_equal('fobar', getline('.'))
+  call feedkeys("Sfob\<C-X>\<C-f>\<C-N>\<Esc>0", 'tx!')
+  call assert_equal('foobar', getline('.'))
+
+  " can get completion from other buffer
+  set completeopt=fuzzy,menu,menuone
+  vnew
+  call setline(1, ["completeness,", "compatibility", "Composite", "Omnipotent"])
+  wincmd p
+  call feedkeys("Somp\<C-N>\<Esc>0", 'tx!')
+  call assert_equal('completeness', getline('.'))
+  call feedkeys("Somp\<C-N>\<C-N>\<Esc>0", 'tx!')
+  call assert_equal('compatibility', getline('.'))
+  call feedkeys("Somp\<C-P>\<Esc>0", 'tx!')
+  call assert_equal('Omnipotent', getline('.'))
+  call feedkeys("Somp\<C-P>\<C-P>\<Esc>0", 'tx!')
+  call assert_equal('Composite', getline('.'))
+
+  " fuzzy on whole line completion
+  call setline(1, ["world is on fire", "no one can save me but you", 'user can execute', ''])
+  call cursor(4, 1)
+  call feedkeys("Swio\<C-X>\<C-L>\<Esc>0", 'tx!')
+  call assert_equal('world is on fire', getline('.'))
+  call feedkeys("Su\<C-X>\<C-L>\<C-P>\<Esc>0", 'tx!')
+  call assert_equal('no one can save me but you', getline('.'))
+
   " issue #15526
   set completeopt=fuzzy,menuone,menu,noselect
   call setline(1, ['Text', 'ToText', ''])
@@ -2884,6 +2946,7 @@ func Test_complete_fuzzy_match()
   " clean up
   set omnifunc=
   bw!
+  bw!
   set complete& completeopt&
   autocmd! AAAAA_Group
   augroup! AAAAA_Group