qlit: Tighten QLit dict vs QDict comparison

We check that all members of the QLit dictionary are also in the
QDict.  We neglect to check the other direction.

Comparing the number of members suffices, because QDict can't
contain duplicate members, and putting duplicates in a QLit is a
programming error.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170825105913.4060-12-marcandre.lureau@redhat.com>
[Commit message improved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

2 files changed, 30 insertions, 14 deletions

diff --git a/qobject/qlit.c b/qobject/qlit.c
index b1d9146220..dc0015f76c 100644
--- a/qobject/qlit.c
+++ b/qobject/qlit.c
@@ -41,6 +41,27 @@ static void compare_helper(QObject *obj, void *opaque)
         qlit_equal_qobject(&helper->objs[helper->index++], obj);
 }
 
+static bool qlit_equal_qdict(const QLitObject *lhs, const QDict *qdict)
+{
+    int i;
+
+    for (i = 0; lhs->value.qdict[i].key; i++) {
+        QObject *obj = qdict_get(qdict, lhs->value.qdict[i].key);
+
+        if (!qlit_equal_qobject(&lhs->value.qdict[i].value, obj)) {
+            return false;
+        }
+    }
+
+    /* Note: the literal qdict must not contain duplicates, this is
+     * considered a programming error and it isn't checked here. */
+    if (qdict_size(qdict) != i) {
+        return false;
+    }
+
+    return true;
+}
+
 bool qlit_equal_qobject(const QLitObject *lhs, const QObject *rhs)
 {
     if (!rhs || lhs->type != qobject_type(rhs)) {
@@ -55,20 +76,8 @@ bool qlit_equal_qobject(const QLitObject *lhs, const QObject *rhs)
     case QTYPE_QSTRING:
         return (strcmp(lhs->value.qstr,
                        qstring_get_str(qobject_to_qstring(rhs))) == 0);
-    case QTYPE_QDICT: {
-        int i;
-
-        for (i = 0; lhs->value.qdict[i].key; i++) {
-            QObject *obj = qdict_get(qobject_to_qdict(rhs),
-                                     lhs->value.qdict[i].key);
-
-            if (!qlit_equal_qobject(&lhs->value.qdict[i].value, obj)) {
-                return false;
-            }
-        }
-
-        return true;
-    }
+    case QTYPE_QDICT:
+        return qlit_equal_qdict(lhs, qobject_to_qdict(rhs));
     case QTYPE_QLIST: {
         QListCompareHelper helper;
 
diff --git a/tests/check-qlit.c b/tests/check-qlit.c
index d2422bbaf0..d2ecc200d3 100644
--- a/tests/check-qlit.c
+++ b/tests/check-qlit.c
@@ -28,6 +28,11 @@ static QLitObject qlit = QLIT_QDICT(((QLitDictEntry[]) {
     { },
 }));
 
+static QLitObject qlit_foo = QLIT_QDICT(((QLitDictEntry[]) {
+    { "foo", QLIT_QNUM(42) },
+    { },
+}));
+
 static QObject *make_qobject(void)
 {
     QDict *qdict = qdict_new();
@@ -51,6 +56,8 @@ static void qlit_equal_qobject_test(void)
 
     g_assert(qlit_equal_qobject(&qlit, qobj));
 
+    g_assert(!qlit_equal_qobject(&qlit_foo, qobj));
+
     qobject_decref(qobj);
 }