From 03ab94b0e7a549bcf839639438f782a47522ffa7 Mon Sep 17 00:00:00 2001
From: Igor Mironchik <igor.mironchik@gmail.com>
Date: Thu, 24 May 2018 15:59:23 +0300
Subject: [PATCH] Deregister QTextCodec on destruction

QTextCodec automatically deregisters on destruction now.

[ChangeLog][QtCore][QTextCodec] QTextCodec automatically
deregisters on destruction now.

Task-number: QTBUG-56203
Change-Id: Ic9a66c512642c9913aa27ea5167b9f7341e7f0fe
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 src/corelib/codecs/qtextcodec.cpp              | 18 ++++++++++++++++++
 src/corelib/kernel/qcoreglobaldata.cpp         |  5 ++++-
 .../codecs/qtextcodec/tst_qtextcodec.cpp       |  7 ++++++-
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/corelib/codecs/qtextcodec.cpp b/src/corelib/codecs/qtextcodec.cpp
index 1541c498e6..7951e95db5 100644
--- a/src/corelib/codecs/qtextcodec.cpp
+++ b/src/corelib/codecs/qtextcodec.cpp
@@ -492,6 +492,24 @@ QTextCodec::QTextCodec()
 */
 QTextCodec::~QTextCodec()
 {
+    QCoreGlobalData *globalData = QCoreGlobalData::instance();
+    if (!globalData)
+        return;
+
+    globalData->codecForLocale.testAndSetRelaxed(this, nullptr);
+
+    QMutexLocker locker(textCodecsMutex());
+
+    globalData->allCodecs.removeOne(this);
+
+    auto it = globalData->codecCache.cbegin();
+
+    while (it != globalData->codecCache.cend()) {
+        if (it.value() == this)
+            it = globalData->codecCache.erase(it);
+        else
+            ++it;
+    }
 }
 
 /*!
diff --git a/src/corelib/kernel/qcoreglobaldata.cpp b/src/corelib/kernel/qcoreglobaldata.cpp
index e2087b9e64..88a45ef4ee 100644
--- a/src/corelib/kernel/qcoreglobaldata.cpp
+++ b/src/corelib/kernel/qcoreglobaldata.cpp
@@ -55,7 +55,10 @@ QCoreGlobalData::~QCoreGlobalData()
 {
 #if QT_CONFIG(textcodec)
     codecForLocale = 0;
-    for (QList<QTextCodec *>::const_iterator it = allCodecs.constBegin(); it != allCodecs.constEnd(); ++it)
+    QList<QTextCodec *> tmp = allCodecs;
+    allCodecs.clear();
+    codecCache.clear();
+    for (QList<QTextCodec *>::const_iterator it = tmp.constBegin(); it != tmp.constEnd(); ++it)
         delete *it;
 #endif
 }
diff --git a/tests/auto/corelib/codecs/qtextcodec/tst_qtextcodec.cpp b/tests/auto/corelib/codecs/qtextcodec/tst_qtextcodec.cpp
index f8f9387abb..b3b7c082cc 100644
--- a/tests/auto/corelib/codecs/qtextcodec/tst_qtextcodec.cpp
+++ b/tests/auto/corelib/codecs/qtextcodec/tst_qtextcodec.cpp
@@ -2429,7 +2429,7 @@ void tst_QTextCodec::userCodec()
     QVERIFY(!QTextCodec::availableCodecs().contains("UserCodec"));
     QVERIFY(!QTextCodec::codecForName("UserCodec"));
 
-    QTextCodec *codec = new UserCodec;
+    UserCodec *codec = new UserCodec;
     executedOnce = true;
 
     QList<QByteArray> availableCodecs = QTextCodec::availableCodecs();
@@ -2448,6 +2448,11 @@ void tst_QTextCodec::userCodec()
 
     pcodec = QTextCodec::codecForMib(5000);
     QCOMPARE(pcodec, codec);
+
+    delete codec;
+
+    pcodec = QTextCodec::codecForName("UserCodec");
+    QCOMPARE(pcodec, nullptr);
 }
 
 struct DontCrashAtExit {