patch 9.0.1846: [security] crash in fullcommand

Problem:  crash in fullcommand
Solution: Check for typeval correctly

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 32d52ab..10d979d 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -4087,7 +4087,7 @@
 		|| check_for_opt_bool_arg(argvars, 1) == FAIL))
 	return;
 
-    name = argvars[0].vval.v_string;
+    name = tv_get_string(&argvars[0]);
     if (name == NULL)
 	return;
 
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 0eda5de..ab1dbf3 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -3607,4 +3607,9 @@
   let &encoding = save_enc
 endfunc
 
+func Test_fullcommand()
+  " this used to crash vim
+  call assert_equal('', fullcommand(10))
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
index 3de6046..5cde7c1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -700,6 +700,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1846,
+/**/
     1845,
 /**/
     1844,