tests: Expose regression in QemuOpts visitor

Commit 15c2f669 broke the ability of the QemuOpts visitor to
flag extra input parameters, but the regression went unnoticed
because of missing testsuite coverage.  Add a test to cover this;
take the approach already used in 9cb8ef36 of adding a test that
passes (to avoid breaking bisection) but marks with BUG the
behavior that we don't like, so that the actual impact of the
fix in a later patch is easier to see.

CC: qemu-stable@nongnu.org
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Message-Id: <20170322144525.18964-2-eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
(cherry picked from commit 76861f6b)
 Conflicts:
	tests/test-opts-visitor.c
 * drop context dep on 9cb8ef36 and a9416dc6 tests
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

tests/test-opts-visitor.c

@@ -172,6 +172,24 @@ expect_u64_max(OptsVisitorFixture *f, gconstpointer test_data)
 
 /* test cases */
 
+static void
+test_opts_dict_unvisited(void)
+{
+    QemuOpts *opts;
+    Visitor *v;
+    UserDefOptions *userdef;
+
+    opts = qemu_opts_parse(qemu_find_opts("userdef"), "i64x=0,bogus=1", false,
+                           &error_abort);
+
+    v = opts_visitor_new(opts);
+    /* BUG: bogus should be diagnosed */
+    visit_type_UserDefOptions(v, NULL, &userdef, &error_abort);
+    visit_free(v);
+    qemu_opts_del(opts);
+    qapi_free_UserDefOptions(userdef);
+}
+
 int
 main(int argc, char **argv)
 {
@@ -263,6 +281,8 @@ main(int argc, char **argv)
     add_test("/visitor/opts/i64/range/2big/full", &expect_fail,
              "i64=-0x8000000000000000-0x7fffffffffffffff");
 
+    g_test_add_func("/visitor/opts/dict/unvisited", test_opts_dict_unvisited);
+
     g_test_run();
     return 0;
 }