vim-patch:8.2.4713: plugins cannot track text scrolling

Problem:    Plugins cannot track text scrolling.
Solution:   Add the WinScrolled event. (closes vim/vim#10102)
https://github.com/vim/vim/commit/0937182d49fa8db50cec42785f22f1031760a0bd

Skip User event in autocmd.txt, not needed unless #10689 is reverted.

1 files changed, 55 insertions, 0 deletions

diff --git a/src/nvim/testdir/test_autocmd.vim b/src/nvim/testdir/test_autocmd.vim
index e3362cd28f..4b4f6ad3d3 100644
--- a/src/nvim/testdir/test_autocmd.vim
+++ b/src/nvim/testdir/test_autocmd.vim
@@ -3,6 +3,7 @@
 source shared.vim
 source check.vim
 source term_util.vim
+source screendump.vim
 
 func s:cleanup_buffers() abort
   for bnr in range(1, bufnr('$'))
@@ -260,6 +261,60 @@ func Test_win_tab_autocmd()
   unlet g:record
 endfunc
 
+func Test_WinScrolled()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+	set nowrap scrolloff=0
+        for ii in range(1, 18)
+          call setline(ii, repeat(nr2char(96 + ii), ii * 2))
+        endfor
+        let win_id = win_getid()
+        let g:matched = v:false
+        execute 'au WinScrolled' win_id 'let g:matched = v:true'
+        let g:scrolled = 0
+        au WinScrolled * let g:scrolled += 1
+        au WinScrolled * let g:amatch = str2nr(expand('<amatch>'))
+        au WinScrolled * let g:afile = str2nr(expand('<afile>'))
+  END
+  call writefile(lines, 'Xtest_winscrolled')
+  let buf = RunVimInTerminal('-S Xtest_winscrolled', {'rows': 6})
+
+  call term_sendkeys(buf, ":echo g:scrolled\<CR>")
+  call WaitForAssert({-> assert_match('^0 ', term_getline(buf, 6))}, 1000)
+
+  " Scroll left/right in Normal mode.
+  call term_sendkeys(buf, "zlzh:echo g:scrolled\<CR>")
+  call WaitForAssert({-> assert_match('^2 ', term_getline(buf, 6))}, 1000)
+
+  " Scroll up/down in Normal mode.
+  call term_sendkeys(buf, "\<c-e>\<c-y>:echo g:scrolled\<CR>")
+  call WaitForAssert({-> assert_match('^4 ', term_getline(buf, 6))}, 1000)
+
+  " Scroll up/down in Insert mode.
+  call term_sendkeys(buf, "Mi\<c-x>\<c-e>\<Esc>i\<c-x>\<c-y>\<Esc>")
+  call term_sendkeys(buf, ":echo g:scrolled\<CR>")
+  call WaitForAssert({-> assert_match('^6 ', term_getline(buf, 6))}, 1000)
+
+  " Scroll the window horizontally to focus the last letter of the third line
+  " containing only six characters. Moving to the previous and shorter lines
+  " should trigger another autocommand as Vim has to make them visible.
+  call term_sendkeys(buf, "5zl2k")
+  call term_sendkeys(buf, ":echo g:scrolled\<CR>")
+  call WaitForAssert({-> assert_match('^8 ', term_getline(buf, 6))}, 1000)
+
+  " Ensure the command was triggered for the specified window ID.
+  call term_sendkeys(buf, ":echo g:matched\<CR>")
+  call WaitForAssert({-> assert_match('^v:true ', term_getline(buf, 6))}, 1000)
+
+  " Ensure the expansion of <amatch> and <afile> matches the window ID.
+  call term_sendkeys(buf, ":echo g:amatch == win_id && g:afile == win_id\<CR>")
+  call WaitForAssert({-> assert_match('^v:true ', term_getline(buf, 6))}, 1000)
+
+  call StopVimInTerminal(buf)
+  call delete('Xtest_winscrolled')
+endfunc
+
 func Test_WinClosed()
   " Test that the pattern is matched against the closed window's ID, and both
   " <amatch> and <afile> are set to it.