patch 8.0.1779: deleting in a block selection causes problems

Problem:    Deleting in a block selection causes problems.
Solution:   Check the length of the line before adding bd.textcol and
            bd.textlen. (Christian Brabandt, closes #2825)
diff --git a/src/testdir/test_blockedit.vim b/src/testdir/test_blockedit.vim
index 4a8d599..527224c 100644
--- a/src/testdir/test_blockedit.vim
+++ b/src/testdir/test_blockedit.vim
@@ -16,5 +16,18 @@
   bwipe!
 endfunc
 
+func Test_blockinsert_delete()
+  new
+  let _bs = &bs
+  set bs=2
+  call setline(1, ['case Arg is ', '        when Name_Async,', '        when Name_Num_Gangs,', 'end if;'])
+  exe "norm! ggjVj\<c-v>$o$A\<bs>\<esc>"
+  "call feedkeys("Vj\<c-v>$o$A\<bs>\<esc>", 'ti')
+  call assert_equal(["case Arg is ", "        when Name_Async", "        when Name_Num_Gangs,", "end if;"],
+        \ getline(1,'$'))
+  " reset to sane state
+  let &bs = _bs
+  bwipe!
+endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab