vim-patch:8.2.2058: using mkview/loadview changes the jumplist

Problem:    Using mkview/loadview changes the jumplist.
Solution:   Use ":keepjumps".  Don't let ":badd" or ":balt" change the
            jumplist. (closes vim/vim#7371)
3482be6a33

Definition for BufWinEnter autocmd in Test_mkview_loadview_jumplist()
was moved down a few lines until after the views are written, as in
Nvim, :loadview throws if the view file can't be opened.

src/nvim/ex_docmd.c

@@ -7345,7 +7345,9 @@ do_exedit(
     else if (eap->cmdidx == CMD_enew)
       readonlymode = FALSE;         /* 'readonly' doesn't make sense in an
                                        empty buffer */
-    setpcmark();
+    if (eap->cmdidx != CMD_balt && eap->cmdidx != CMD_badd) {
+      setpcmark();
+    }
     if (do_ecmd(0, (eap->cmdidx == CMD_enew ? NULL : eap->arg),
                 NULL, eap, eap->do_ecmd_lnum,
                 (buf_hide(curbuf) ? ECMD_HIDE : 0)

src/nvim/ex_session.c

@@ -449,9 +449,9 @@ static int put_view(
                 "let s:l = %" PRId64 " - ((%" PRId64
                 " * winheight(0) + %" PRId64 ") / %" PRId64 ")\n"
                 "if s:l < 1 | let s:l = 1 | endif\n"
-                "exe s:l\n"
+                "keepjumps exe s:l\n"
                 "normal! zt\n"
-                "%" PRId64 "\n",
+                "keepjumps %" PRId64 "\n",
                 (int64_t)wp->w_cursor.lnum,
                 (int64_t)(wp->w_cursor.lnum - wp->w_topline),
                 (int64_t)(wp->w_height_inner / 2),

src/nvim/testdir/test_mksession.vim

@@ -399,6 +399,58 @@ func Test_mkview_no_file_name()
   %bwipe
 endfunc
 
+func Test_mkview_loadview_jumplist()
+  set viewdir=Xviewdir
+  au BufWinLeave * silent mkview
+  " au BufWinEnter * silent loadview
+
+  edit Xfile1
+  call setline(1, ['a', 'bbbbbbb', 'c'])
+  normal j3l
+  call assert_equal([2, 4], getcurpos()[1:2])
+  write
+
+  edit Xfile2
+  call setline(1, ['d', 'eeeeeee', 'f'])
+  normal j5l
+  call assert_equal([2, 6], getcurpos()[1:2])
+  write
+
+  edit Xfile3
+  call setline(1, ['g', 'h', 'iiiii'])
+  normal jj3l
+  call assert_equal([3, 4], getcurpos()[1:2])
+  write
+
+  " The commented :au above was moved here so that :mkview (on BufWinLeave) can
+  " run before :loadview. This is needed because Nvim's :loadview raises E484 if
+  " the view can't be opened, while Vim's silently fails instead.
+  au BufWinEnter * silent loadview
+
+  edit Xfile1
+  call assert_equal([2, 4], getcurpos()[1:2])
+  edit Xfile2
+  call assert_equal([2, 6], getcurpos()[1:2])
+  edit Xfile3
+  call assert_equal([3, 4], getcurpos()[1:2])
+
+  exe "normal \<C-O>"
+  call assert_equal('Xfile2', expand('%'))
+  call assert_equal([2, 6], getcurpos()[1:2])
+  exe "normal \<C-O>"
+  call assert_equal('Xfile1', expand('%'))
+  call assert_equal([2, 4], getcurpos()[1:2])
+
+  au! BufWinLeave
+  au! BufWinEnter
+  bwipe!
+  call delete('Xviewdir', 'rf')
+  call delete('Xfile1')
+  call delete('Xfile2')
+  call delete('Xfile3')
+  set viewdir&
+endfunc
+
 " A clean session (one empty buffer, one window, and one tab) should not
 " set any error messages when sourced because no commands should fail.
 func Test_mksession_no_errmsg()
@@ -689,4 +741,27 @@ func Test_scrolloff()
   set sessionoptions&
 endfunc
 
+func Test_altfile()
+  edit Xone
+  split Xtwo
+  edit Xtwoalt
+  edit #
+  wincmd w
+  edit Xonealt
+  edit #
+  mksession! Xtest_altfile
+  only
+  bwipe Xonealt
+  bwipe Xtwoalt
+  bwipe!
+  source Xtest_altfile
+  call assert_equal('Xone', bufname())
+  call assert_equal('Xonealt', bufname('#'))
+  wincmd w
+  call assert_equal('Xtwo', bufname())
+  call assert_equal('Xtwoalt', bufname('#'))
+  only
+  bwipe!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab