patch 8.2.2176: crash with a sequence of fold commands

Problem:    Crash with a sequence of fold commands.
Solution:   Bail out when there are no folds at all.  Add a test (Dominique
            Pellé) (closes #7515)
diff --git a/src/fold.c b/src/fold.c
index 82ce7e7..f889f4c 100644
--- a/src/fold.c
+++ b/src/fold.c
@@ -916,7 +916,7 @@
 	{
 	    if (!foldFind(gap, curwin->w_cursor.lnum - lnum_off, &fp))
 	    {
-		if (!updown)
+		if (!updown || gap->ga_len == 0)
 		    break;
 
 		// When moving up, consider a fold above the cursor; when
diff --git a/src/testdir/test_fold.vim b/src/testdir/test_fold.vim
index 505ad02..b978fc0 100644
--- a/src/testdir/test_fold.vim
+++ b/src/testdir/test_fold.vim
@@ -852,4 +852,11 @@
   bwipe!
 endfunc
 
+" this was crashing
+func Test_fold_create_delete()
+  new
+  norm zFzFzdzj
+  bwipe!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
index e9c65bc..5ed39fe 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2176,
+/**/
     2175,
 /**/
     2174,