Index: kdecore/localization/klocale_p.h
===================================================================
--- kdecore/localization/klocale_p.h	(Revision 0)
+++ kdecore/localization/klocale_p.h	(Revision 1032185)
@@ -0,0 +1,10 @@
+#ifndef KLOCALE_P_H
+#define KLOCALE_P_H
+
+class QMutex;
+
+// Used by both KLocale and KLocalizedString, since they call each other.
+QMutex* kLocaleMutex();
+
+#endif /* KLOCALE_P_H */
+
Index: kdecore/localization/klocalizedstring.cpp
===================================================================
--- kdecore/localization/klocalizedstring.cpp	(Revision 1032184)
+++ kdecore/localization/klocalizedstring.cpp	(Revision 1032185)
@@ -24,6 +24,7 @@
 #include <kglobal.h>
 #include <kdebug.h>
 #include <klocale.h>
+#include <klocale_p.h>
 #include <kcomponentdata.h>
 #include <klibrary.h>
 #include <kstandarddirs.h>
@@ -126,8 +127,6 @@
 
     QHash<QString, KuitSemantics*> formatters;
 
-    QMutex mutex;
-
     KLocalizedStringPrivateStatics () :
         theFence("|/|"),
         startInterp("$["),
@@ -144,9 +143,7 @@
 
         translits(),
 
-        formatters(),
-
-        mutex(QMutex::Recursive)
+        formatters()
     {}
 
     ~KLocalizedStringPrivateStatics ()
@@ -216,7 +213,7 @@
 QString KLocalizedStringPrivate::toString (const KLocale *locale) const
 {
     KLocalizedStringPrivateStatics *s = staticsKLSP;
-    QMutexLocker lock(&s->mutex);
+    QMutexLocker lock(kLocaleMutex());
 
     // Assure the message has been supplied.
     if (msg.isEmpty())
@@ -474,7 +471,7 @@
                                              const QString &ctxt) const
 {
     KLocalizedStringPrivateStatics *s = staticsKLSP;
-    QMutexLocker lock(&s->mutex);
+    QMutexLocker lock(kLocaleMutex());
 
     QString final = text;
 
@@ -499,7 +496,7 @@
                                                        bool &fallback) const
 {
     KLocalizedStringPrivateStatics *s = staticsKLSP;
-    QMutexLocker lock(&s->mutex);
+    QMutexLocker lock(kLocaleMutex());
 
     if (s->ktrs == NULL)
         // Scripting engine not available.
@@ -564,7 +561,7 @@
     // fallback is set to true if Transcript evaluation requested so.
 
     KLocalizedStringPrivateStatics *s = staticsKLSP;
-    QMutexLocker lock(&s->mutex);
+    QMutexLocker lock(kLocaleMutex());
 
     result.clear();
     fallback = false;
@@ -716,7 +713,7 @@
 QVariant KLocalizedStringPrivate::segmentToValue (const QString &seg) const
 {
     KLocalizedStringPrivateStatics *s = staticsKLSP;
-    QMutexLocker lock(&s->mutex);
+    QMutexLocker lock(kLocaleMutex());
 
     // Return invalid variant if segment is either not a proper
     // value reference, or the reference is out of bounds.
@@ -751,7 +748,7 @@
                                                  const QString &final) const
 {
     KLocalizedStringPrivateStatics *s = staticsKLSP;
-    QMutexLocker lock(&s->mutex);
+    QMutexLocker lock(kLocaleMutex());
 
     if (s->ktrs == NULL)
         // Scripting engine not available.
@@ -945,7 +942,7 @@
 void KLocalizedStringPrivate::loadTranscript ()
 {
     KLocalizedStringPrivateStatics *s = staticsKLSP;
-    QMutexLocker lock(&s->mutex);
+    QMutexLocker lock(kLocaleMutex());
 
     s->loadTranscriptCalled = true;
     s->ktrs = NULL; // null indicates that Transcript is not available
@@ -979,7 +976,8 @@
         return;
     }
     KLocalizedStringPrivateStatics *s = staticsKLSP;
-    QMutexLocker lock(&s->mutex);
+    // Very important: do not the mutex here.
+    //QMutexLocker lock(kLocaleMutex());
 
     // Find script modules for all included language/catalogs that have them,
     // and remember their paths.
Index: kdecore/localization/klocale.cpp
===================================================================
--- kdecore/localization/klocale.cpp	(Revision 1032184)
+++ kdecore/localization/klocale.cpp	(Revision 1032185)
@@ -22,6 +22,7 @@
 */
 
 #include "klocale.h"
+#include "klocale_p.h"
 
 #include <config.h>
 
@@ -242,7 +243,6 @@
   // Handling of translation catalogs
   QStringList languageList;
 
-  QMutex* mutex;
   QList<KCatalogName> catalogNames; // list of all catalogs (regardless of language)
   QList<KCatalog> catalogs; // list of all found catalogs, one instance per catalog name and language
   int numberOfSysCatalogs; // number of catalogs that each app draws from
@@ -276,7 +276,6 @@
 KLocalePrivate::KLocalePrivate(const QString& catalog, KConfig *config, const QString &language_, const QString &country_)
     : language(language_),
       country(country_),
-      mutex(new QMutex(QMutex::Recursive)),
       useTranscript(false),
       codecForEncoding(0),
       languages(0), calendar(0),
@@ -311,7 +310,7 @@
 void KLocalePrivate::initMainCatalogs()
 {
   KLocaleStaticData *s = staticData;
-  QMutexLocker lock(mutex);
+  QMutexLocker lock(kLocaleMutex());
 
   if (!s->maincatalog.isEmpty()) {
       // If setMainCatalog was called, then we use that (e.g. korgac calls setMainCatalog("korganizer") to use korganizer.po)
@@ -541,7 +540,7 @@
 
 bool KLocalePrivate::setLanguage(const QString & _language, KConfig *config)
 {
-  QMutexLocker lock(mutex);
+  QMutexLocker lock(kLocaleMutex());
   languageList.removeAll( _language );
   languageList.prepend( _language ); // let us consider this language to be the most important one
 
@@ -563,7 +562,7 @@
 
 bool KLocalePrivate::setLanguage(const QStringList & languages)
 {
-  QMutexLocker lock(mutex);
+  QMutexLocker lock(kLocaleMutex());
   // This list might contain
   // 1) some empty strings that we have to eliminate
   // 2) duplicate entries like in de:fr:de, where we have to keep the first occurrence of a language in order
@@ -685,7 +684,7 @@
 
 void KLocale::insertCatalog( const QString & catalog )
 {
-  QMutexLocker lock(d->mutex);
+  QMutexLocker lock(kLocaleMutex());
     int pos = d->catalogNames.indexOf(KCatalogName(catalog));
     if (pos != -1) {
         ++d->catalogNames[pos].loadCount;
@@ -736,7 +735,7 @@
 
 void KLocale::removeCatalog(const QString &catalog)
 {
-    QMutexLocker lock(d->mutex);
+    QMutexLocker lock(kLocaleMutex());
     int pos = d->catalogNames.indexOf(KCatalogName(catalog));
     if (pos == -1)
         return;
@@ -749,7 +748,7 @@
 
 void KLocale::setActiveCatalog(const QString &catalog)
 {
-    QMutexLocker lock(d->mutex);
+    QMutexLocker lock(kLocaleMutex());
     int pos = d->catalogNames.indexOf(KCatalogName(catalog));
     if (pos == -1)
         return;
@@ -759,7 +758,6 @@
 
 KLocale::~KLocale()
 {
-    delete d->mutex;
     delete d->calendar;
     delete d->languages;
     delete d;
@@ -788,7 +786,7 @@
                 << "Fix the program" << endl;
   }
 
-  QMutexLocker locker(mutex);
+  QMutexLocker locker(kLocaleMutex());
   // determine the fallback string
   QString fallback;
   if ( msgid_plural == NULL )
@@ -1370,7 +1368,7 @@
     //Kibi-byte             KiB             2^10    1,024 bytes
 
     if (d->byteSizeFmt.size() == 0) {
-        QMutexLocker lock(d->mutex);
+        QMutexLocker lock(kLocaleMutex());
         // Pretranslated format strings for byte sizes.
         #define CACHEBYTEFMT(x) { \
             QString s; \
@@ -2568,7 +2566,6 @@
 {
   d->languages = 0; // Don't copy languages
   d->calendar = 0; // Don't copy the calendar
-  d->mutex = 0; // Don't copy the mutex
 }
 
 KLocale & KLocale::operator=(const KLocale & rhs)
@@ -2583,8 +2580,7 @@
 
 void KLocale::copyCatalogsTo(KLocale *locale)
 {
-    QMutexLocker lock(d->mutex);
-    QMutexLocker lockOther(locale->d->mutex);
+    QMutexLocker lock(kLocaleMutex());
     locale->d->catalogNames = d->catalogNames;
     locale->d->updateCatalogs();
 }
@@ -2656,3 +2652,9 @@
 {
     return d->dateTimeDigitSet;
 }
+
+Q_GLOBAL_STATIC_WITH_ARGS(QMutex, s_kLocaleMutex, (QMutex::Recursive))
+QMutex* kLocaleMutex()
+{
+    return s_kLocaleMutex();
+}