patch 8.2.0261: some code not covered by tests

Problem:    Some code not covered by tests.
Solution:   Add test cases. (Yegappan Lakshmanan, closes #5645)
diff --git a/src/testdir/test_quickfix.vim b/src/testdir/test_quickfix.vim
index cc5ee80..d3f2e3a 100644
--- a/src/testdir/test_quickfix.vim
+++ b/src/testdir/test_quickfix.vim
@@ -538,6 +538,15 @@
   10Xcc
   call assert_equal(11, line('.'))
   call assert_equal('Xqftestfile2', bufname('%'))
+  Xopen
+  call cursor(2, 1)
+  if a:cchar == 'c'
+    .cc
+  else
+    .ll
+  endif
+  call assert_equal(6, line('.'))
+  call assert_equal('Xqftestfile1', bufname('%'))
 
   " Jumping to an error from the error window (when only the error window is
   " present)