patch 8.1.0320: too much 'incsearch' highlight for pat matching everything

Problem:    Too much 'incsearch' highlight for pattern matching everything.
Solution:   Add the skiplen to the command and remove the line range.
            (Christian Brabandt)  Check for empty pattern earlier.
diff --git a/src/testdir/test_search.vim b/src/testdir/test_search.vim
index 9ede26d..ba2d21a 100644
--- a/src/testdir/test_search.vim
+++ b/src/testdir/test_search.vim
@@ -913,6 +913,14 @@
   call VerifyScreenDump(buf, 'Test_incsearch_substitute_08', {})
   call term_sendkeys(buf, "\<Esc>")
 
+  " Only \v handled as empty pattern, does not move cursor
+  call term_sendkeys(buf, '3G4G')
+  call term_sendkeys(buf, ":nohlsearch\<CR>")
+  call term_sendkeys(buf, ':6,7s/\v')
+  sleep 100m
+  call VerifyScreenDump(buf, 'Test_incsearch_substitute_09', {})
+  call term_sendkeys(buf, "\<Esc>")
+
   call StopVimInTerminal(buf)
   call delete('Xis_subst_script')
 endfunc