vim-patch:8.2.4645: 'shortmess' changed when session does not store options (#17908)

Problem:    'shortmess' changed when session does not store options.
Solution:   Save and restore 'shortmess' if needed. (James Charti,
            closes vim/vim#10037)
https://github.com/vim/vim/commit/fd01280d01c2270a320d8c962d24140a8176a400

1 files changed, 43 insertions, 0 deletions

diff --git a/src/nvim/testdir/test_mksession.vim b/src/nvim/testdir/test_mksession.vim
index 798cb9e54f..5dbe2cd366 100644
--- a/src/nvim/testdir/test_mksession.vim
+++ b/src/nvim/testdir/test_mksession.vim
@@ -795,6 +795,49 @@ func Test_mksession_winminheight()
   set sessionoptions&
 endfunc
 
+" Test for mksession with and without options restores shortmess
+func Test_mksession_shortmess()
+  " Without options
+  set sessionoptions-=options
+  split
+  mksession! Xtest_mks.out
+  let found_save = 0
+  let found_restore = 0
+  let lines = readfile('Xtest_mks.out')
+  for line in lines
+    let line = trim(line)
+
+    if line ==# 'let s:shortmess_save = &shortmess'
+      let found_save += 1
+    endif
+
+    if found_save !=# 0 && line ==# 'let &shortmess = s:shortmess_save'
+      let found_restore += 1
+    endif
+  endfor
+  call assert_equal(1, found_save)
+  call assert_equal(1, found_restore)
+  call delete('Xtest_mks.out')
+  close
+  set sessionoptions&
+
+  " With options
+  set sessionoptions+=options
+  split
+  mksession! Xtest_mks.out
+  let found_restore = 0
+  let lines = readfile('Xtest_mks.out')
+  for line in lines
+    if line =~# 's:shortmess_save'
+      let found_restore += 1
+    endif
+  endfor
+  call assert_equal(0, found_restore)
+  call delete('Xtest_mks.out')
+  close
+  set sessionoptions&
+endfunc
+
 " Test for mksession with 'compatible' option
 func Test_mksession_compatible()
   throw 'skipped: Nvim does not support "compatible" option'