vim-patch:8.2.4980: when 'shortmess' contains 'A' loading session may still warn (#18636)

Problem:    When 'shortmess' contains 'A' loading a session may still warn for
            an existing swap file. (Melker Österberg)
Solution:   Keep the 'A' flag to 'shortmess' in the session file.
            (closes vim/vim#10443)
https://github.com/vim/vim/commit/aaadb5b6f76ea03e5eb460121f3dbf46ad04ce50

Use readfile() with "B" flag in test as readblob() needs patch 8.2.2343.

1 files changed, 24 insertions, 0 deletions

diff --git a/src/nvim/testdir/test_mksession.vim b/src/nvim/testdir/test_mksession.vim
index 5dbe2cd366..c55ba391a5 100644
--- a/src/nvim/testdir/test_mksession.vim
+++ b/src/nvim/testdir/test_mksession.vim
@@ -838,6 +838,30 @@ func Test_mksession_shortmess()
   set sessionoptions&
 endfunc
 
+" Test that when Vim loading session has 'A' in 'shortmess' it does not
+" complain about an existing swapfile.
+func Test_mksession_shortmess_with_A()
+  edit Xtestfile
+  write
+  let fname = swapname('%')
+  " readblob() needs patch 8.2.2343
+  " let cont = readblob(fname)
+  let cont = readfile(fname, 'B')
+  set sessionoptions-=options
+  mksession Xtestsession
+  bwipe!
+
+  " Recreate the swap file to pretend the file is being edited
+  call writefile(cont, fname)
+  set shortmess+=A
+  source Xtestsession
+
+  set shortmess&
+  set sessionoptions&
+  call delete('Xtestsession')
+  call delete(fname)
+endfunc
+
 " Test for mksession with 'compatible' option
 func Test_mksession_compatible()
   throw 'skipped: Nvim does not support "compatible" option'