From 2caf90cb2b4c16ee6f3b67a19d9c810f2a1e9aab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
Date: Wed, 7 Mar 2018 21:10:38 -0500
Subject: [PATCH] qlit: Tighten QLit list vs QList comparison

We check that all members of the QLit list are also in the QList. We
neglect to check the other direction. Fix that.

While there, use QLIST_FOREACH_ENTRY() to simplify the code and break
the loop on the first mismatch.

Backports commit cbb654052600c376d5ee3401c98a25d09d11a154 from qemu
---
 qemu/qobject/qlit.c | 53 ++++++++++++++++-----------------------------
 1 file changed, 19 insertions(+), 34 deletions(-)

diff --git a/qemu/qobject/qlit.c b/qemu/qobject/qlit.c
index 54161e26..c11e9c4f 100644
--- a/qemu/qobject/qlit.c
+++ b/qemu/qobject/qlit.c
@@ -23,29 +23,6 @@
 #include "qapi/qmp/qobject.h"
 #include "qapi/qmp/qstring.h"
 
-typedef struct QListCompareHelper {
-    int index;
-    QLitObject *objs;
-    bool result;
-} QListCompareHelper;
-
-static void compare_helper(QObject *obj, void *opaque)
-{
-    QListCompareHelper *helper = opaque;
-
-    if (!helper->result) {
-        return;
-    }
-
-    if (helper->objs[helper->index].type == QTYPE_NONE) {
-        helper->result = false;
-        return;
-    }
-
-    helper->result =
-        qlit_equal_qobject(&helper->objs[helper->index++], obj);
-}
-
 static bool qlit_equal_qdict(const QLitObject *lhs, const QDict *qdict)
 {
     int i;
@@ -67,6 +44,23 @@ static bool qlit_equal_qdict(const QLitObject *lhs, const QDict *qdict)
     return true;
 }
 
+static bool qlit_equal_qlist(const QLitObject *lhs, const QList *qlist)
+{
+    QListEntry *e;
+    int i = 0;
+
+    QLIST_FOREACH_ENTRY(qlist, e) {
+        QObject *obj = qlist_entry_obj(e);
+
+        if (!qlit_equal_qobject(&lhs->value.qlist[i], obj)) {
+            return false;
+        }
+        i++;
+    }
+
+    return !e && lhs->value.qlist[i].type == QTYPE_NONE;
+}
+
 bool qlit_equal_qobject(const QLitObject *lhs, const QObject *rhs)
 {
     if (!rhs || lhs->type != qobject_type(rhs)) {
@@ -83,17 +77,8 @@ bool qlit_equal_qobject(const QLitObject *lhs, const QObject *rhs)
                        qstring_get_str(qobject_to_qstring(rhs))) == 0);
     case QTYPE_QDICT:
         return qlit_equal_qdict(lhs, qobject_to_qdict(rhs));
-    case QTYPE_QLIST: {
-        QListCompareHelper helper;
-
-        helper.index = 0;
-        helper.objs = lhs->value.qlist;
-        helper.result = true;
-
-        qlist_iter(qobject_to_qlist(rhs), compare_helper, &helper);
-
-        return helper.result;
-    }
+    case QTYPE_QLIST:
+        return qlit_equal_qlist(lhs, qobject_to_qlist(rhs));
     case QTYPE_QNULL:
         return true;
     default: