TQTextCodec: avoid dangling pointer to current locale's codec

This fixes crashes cause by dangling pointer returned from
TQTextCodec::codecForLocale().  That might happen when tqWarning() and
such are called during final cleanup.

Bug: https://mirror.git.trinitydesktop.org/gitea/TDE/tqt3/issues/142
Signed-off-by: Alexander Golubev <fatzer2@gmail.com>

src/codecs/qtextcodec.cpp

@@ -90,12 +90,14 @@
 
 static TQValueList<TQTextCodec*> *all = 0;
 static bool destroying_is_ok; // starts out as 0
+static bool codecs_were_cleansed = 0;
 static TQTextCodec * localeMapper = 0;
 
 class TQTextCodecCleanup {
 public:
     ~TQTextCodecCleanup() {
 	TQTextCodec::deleteAllCodecs();
+	codecs_were_cleansed = TRUE;
     }
 };
 static TQTextCodecCleanup qtextcodec_cleanup;
@@ -140,6 +142,8 @@ void TQTextCodec::deleteAllCodecs()
     ball->clear();
     delete ball;
 
+    localeMapper = 0;
+
     destroying_is_ok = FALSE;
 }
 
@@ -821,7 +825,12 @@ TQTextCodec* TQTextCodec::codecForLocale()
     if ( localeMapper )
 	return localeMapper;
 
-    setup();
+    // codecForLocale() is used by TQString::locale8Bit(), which is used by tqWarning() (and such)
+    // which should be fine to call during final cleanup and in such case we don't want neither to
+    // recreate the codecs again nor complains about codecs being already destroyed.
+    if ( !codecs_were_cleansed ) {
+	setup();
+    }
 
     return localeMapper;
 }
@@ -2906,6 +2915,8 @@ static void realSetup()
 #if defined(QT_CHECK_STATE)
     if ( destroying_is_ok )
 	tqWarning( "TQTextCodec: creating new codec during codec cleanup!" );
+    if ( codecs_were_cleansed )
+	tqWarning( "TQTextCodec: trying to setup codecs after they already been cleansed!" );
 #endif
     all = new TQValueList<TQTextCodec*>;