From d9a914b14df9b43f0437f0dd43c2fb23083b2a31 Mon Sep 17 00:00:00 2001
From: Tim Pope <code@tpope.net>
Date: Sat, 26 Mar 2022 15:32:34 -0400
Subject: [PATCH] Replace 'cursorbind' in blame with manual line syncing

This is the only way to sync the line without also syncing the column.
Syncing the column is particularly problematic when it causes the blame
window to vertically scroll while typing.
---
 autoload/fugitive.vim | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/autoload/fugitive.vim b/autoload/fugitive.vim
index 8775286..4970cdf 100644
--- a/autoload/fugitive.vim
+++ b/autoload/fugitive.vim
@@ -6924,9 +6924,6 @@ function! s:BlameSubcommand(line1, count, range, bang, mods, options) abort
               call add(restore, 'call setwinvar(bufwinnr('.winbufnr(winnr).'),"&foldenable",1)')
             endif
           endif
-          if exists('+cursorbind') && !&l:cursorbind && getwinvar(winnr, '&cursorbind')
-            call setwinvar(winnr, '&cursorbind', 0)
-          endif
           if s:BlameBufnr(winbufnr(winnr)) > 0
             execute winbufnr(winnr).'bdelete'
           endif
@@ -6935,9 +6932,6 @@ function! s:BlameSubcommand(line1, count, range, bang, mods, options) abort
         if !&l:scrollbind
           call add(restore, 'call setwinvar(' . restore_winnr . ',"&scrollbind",0)')
         endif
-        if exists('+cursorbind') && !&l:cursorbind
-          call add(restore, 'call setwinvar(' . restore_winnr . ',"&cursorbind",0)')
-        endif
         if &l:wrap
           call add(restore, 'call setwinvar(' . restore_winnr . ',"&wrap",1)')
         endif
@@ -6945,9 +6939,6 @@ function! s:BlameSubcommand(line1, count, range, bang, mods, options) abort
           call add(restore, 'call setwinvar(' . restore_winnr . ',"&foldenable",1)')
         endif
         setlocal scrollbind nowrap nofoldenable
-        if exists('+cursorbind')
-          setlocal cursorbind
-        endif
         let top = line('w0') + &scrolloff
         let current = line('.')
         exe 'silent keepalt' (a:bang ? s:Mods(mods) . 'split' : s:Mods(mods, 'leftabove') . 'vsplit') s:fnameescape(temp)
@@ -6955,9 +6946,6 @@ function! s:BlameSubcommand(line1, count, range, bang, mods, options) abort
         execute top
         normal! zt
         execute current
-        if exists('+cursorbind')
-          setlocal cursorbind
-        endif
         setlocal nonumber scrollbind nowrap foldcolumn=0 nofoldenable winfixwidth
         if exists('+relativenumber')
           setlocal norelativenumber
@@ -7198,10 +7186,27 @@ function! fugitive#BlameFileType() abort
   call s:BlameMaps(1)
 endfunction
 
+function! s:BlameCursorSync(bufnr, line) abort
+  if a:line == line('.')
+    return
+  endif
+  if get(s:TempState(), 'origin_bufnr') == a:bufnr || get(s:TempState(a:bufnr), 'origin_bufnr') == bufnr('')
+    if &startofline
+      execute a:line
+    else
+      let pos = getpos('.')
+      let pos[1] = a:line
+      call setpos('.', pos)
+    endif
+  endif
+endfunction
+
 augroup fugitive_blame
   autocmd!
   autocmd ColorScheme,GUIEnter * call s:BlameRehighlight()
   autocmd BufWinLeave * execute getwinvar(+bufwinnr(+expand('<abuf>')), 'fugitive_leave')
+  autocmd WinLeave * let s:cursor_for_blame = [bufnr(''), line('.')]
+  autocmd WinEnter * if exists('s:cursor_for_blame') | call call('s:BlameCursorSync', s:cursor_for_blame) | endif
 augroup END
 
 " Section: :GBrowse