From 249eb7ff79b814f0e23074b9a9e955243b677646 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Fri, 30 Sep 2022 14:52:11 +0200
Subject: [PATCH] Qt6: remove or replace QTextCodec

---
 src/Base/InputSource.cpp         | 90 +++++++++++++++++++++++++-------
 src/Base/InputSource.h           |  5 +-
 src/Gui/EditorView.cpp           |  4 ++
 src/Gui/QtAll.h                  |  1 -
 src/Main/MainGui.cpp             | 15 ------
 src/Mod/TechDraw/Gui/QGSPage.cpp |  1 -
 src/Mod/TechDraw/Gui/QGVPage.cpp |  1 -
 7 files changed, 78 insertions(+), 39 deletions(-)

diff --git a/src/Base/InputSource.cpp b/src/Base/InputSource.cpp
index 00d32a3f42..0c4039af80 100644
--- a/src/Base/InputSource.cpp
+++ b/src/Base/InputSource.cpp
@@ -23,6 +23,15 @@
 
 #include "PreCompiled.h"
 
+#include <qglobal.h>
+#if QT_VERSION < 0x060000
+#include <QTextCodec>
+#else
+#include <QByteArray>
+#include <QStringDecoder>
+#include <QStringEncoder>
+#endif
+
 #include "InputSource.h"
 #include "XMLTools.h"
 
@@ -36,11 +45,68 @@ using namespace std;
 // ---------------------------------------------------------------------------
 //  StdInputStream: Constructors and Destructor
 // ---------------------------------------------------------------------------
-StdInputStream::StdInputStream( std::istream& Stream, XERCES_CPP_NAMESPACE_QUALIFIER MemoryManager* const manager )
-  : stream(Stream), fMemoryManager(manager)
+
+#if QT_VERSION < 0x060000
+struct StdInputStream::TextCodec
+{
+    QTextCodec::ConverterState state;
+    TextCodec() {
+        state.flags |= QTextCodec::IgnoreHeader;
+        state.flags |= QTextCodec::ConvertInvalidToNull;
+    }
+
+    void validateBytes(XMLByte* const  toFill, std::streamsize len) {
+        QTextCodec *textCodec = QTextCodec::codecForName("UTF-8");
+        if (textCodec) {
+            const QString text = textCodec->toUnicode(reinterpret_cast<char *>(toFill), static_cast<int>(len), &state);
+            if (state.invalidChars > 0) {
+                // In case invalid characters were found decode back to 'utf-8' and replace
+                // them with '?'
+                // First, Qt replaces invalid characters with '\0' (see ConvertInvalidToNull)
+                // but Xerces doesn't like this because it handles this as termination. Thus,
+                // we have to go through the array and replace '\0' with '?'.
+                std::streamsize pos = 0;
+                QByteArray ba = textCodec->fromUnicode(text);
+                for (int i=0; i<ba.length(); i++, pos++) {
+                    if (pos < len && ba[i] == '\0') {
+                        toFill[i] = '?';
+                    }
+                }
+            }
+        }
+    }
+};
+#else
+struct StdInputStream::TextCodec
+{
+    void validateBytes(XMLByte* const  toFill, std::streamsize len) {
+        QByteArray encodedString(reinterpret_cast<char *>(toFill), static_cast<int>(len));
+        auto toUtf16 = QStringDecoder(QStringDecoder::Utf8);
+        QString text = toUtf16(encodedString);
+        if (toUtf16.hasError()) {
+            // In case invalid characters were found decode back to 'utf-8' and replace
+            // them with '?'
+            // First, Qt replaces invalid characters with '\0'
+            // but Xerces doesn't like this because it handles this as termination. Thus,
+            // we have to go through the array and replace '\0' with '?'.
+            std::streamsize pos = 0;
+            auto fromUtf16 = QStringEncoder(QStringEncoder::Utf8);
+            QByteArray ba = fromUtf16(text);
+            for (int i=0; i<ba.length(); i++, pos++) {
+                if (pos < len && ba[i] == '\0') {
+                    toFill[i] = '?';
+                }
+            }
+        }
+    }
+};
+#endif
+
+StdInputStream::StdInputStream( std::istream& Stream, XERCES_CPP_NAMESPACE_QUALIFIER MemoryManager* const manager )
+  : stream(Stream)
+  , fMemoryManager(manager)
+  , codec(new TextCodec)
 {
-    state.flags |= QTextCodec::IgnoreHeader;
-    state.flags |= QTextCodec::ConvertInvalidToNull;
 }
 
 
@@ -65,21 +131,7 @@ XMLSize_t StdInputStream::readBytes(XMLByte* const  toFill, const XMLSize_t maxT
   stream.read(reinterpret_cast<char *>(toFill), static_cast<std::streamsize>(maxToRead));
   std::streamsize len = stream.gcount();
 
-  QTextCodec *codec = QTextCodec::codecForName("UTF-8");
-  const QString text = codec->toUnicode(reinterpret_cast<char *>(toFill), static_cast<int>(len), &state);
-  if (state.invalidChars > 0) {
-      // In case invalid characters were found decode back to 'utf-8' and replace
-      // them with '?'
-      // First, Qt replaces invalid characters with '\0' (see ConvertInvalidToNull)
-      // but Xerces doesn't like this because it handles this as termination. Thus,
-      // we have to go through the array and replace '\0' with '?'.
-      std::streamsize pos = 0;
-      QByteArray ba = codec->fromUnicode(text);
-      for (int i=0; i<ba.length(); i++, pos++) {
-          if (pos < len && ba[i] == '\0')
-              toFill[i] = '?';
-      }
-  }
+  codec->validateBytes(toFill, len);
 
   return static_cast<XMLSize_t>(len);
 }
diff --git a/src/Base/InputSource.h b/src/Base/InputSource.h
index 88e07caebb..321b741c34 100644
--- a/src/Base/InputSource.h
+++ b/src/Base/InputSource.h
@@ -24,10 +24,10 @@
 #define BASE_IINPUTSOURCE_H
 
 #include <iosfwd>
+#include <memory>
 
 #include <xercesc/util/BinInputStream.hpp>
 #include <xercesc/sax/InputSource.hpp>
-#include <QTextCodec>
 #ifndef FC_GLOBAL_H
 #include <FCGlobal.h>
 #endif
@@ -70,7 +70,8 @@ private :
   // -----------------------------------------------------------------------
   std::istream            &stream;
   XERCES_CPP_NAMESPACE_QUALIFIER MemoryManager* const    fMemoryManager;
-  QTextCodec::ConverterState state;
+  struct TextCodec;
+  std::unique_ptr<TextCodec> codec;
 };
 
 
diff --git a/src/Gui/EditorView.cpp b/src/Gui/EditorView.cpp
index 003e9ad7ef..193b946499 100644
--- a/src/Gui/EditorView.cpp
+++ b/src/Gui/EditorView.cpp
@@ -37,7 +37,9 @@
 # include <QPrintPreviewDialog>
 # include <QSpacerItem>
 # include <QStyle>
+# if QT_VERSION < 0x060000
 # include <QTextCodec>
+# endif
 # include <QTextCursor>
 # include <QTextDocument>
 # include <QTextStream>
@@ -523,7 +525,9 @@ bool EditorView::saveFile()
     if (!file.open(QFile::WriteOnly))
         return false;
     QTextStream ts(&file);
+#if QT_VERSION < 0x060000
     ts.setCodec(QTextCodec::codecForName("UTF-8"));
+#endif
     ts << d->textEdit->document()->toPlainText();
     file.close();
     d->textEdit->document()->setModified(false);
diff --git a/src/Gui/QtAll.h b/src/Gui/QtAll.h
index f119f65a5b..ac4ad3dc71 100644
--- a/src/Gui/QtAll.h
+++ b/src/Gui/QtAll.h
@@ -45,7 +45,6 @@
 #include <QSet>
 #include <QSignalMapper>
 #include <QTemporaryFile>
-#include <qtextcodec.h>
 #include <qtextstream.h>
 #include <qthread.h>
 #include <qthreadpool.h>
diff --git a/src/Main/MainGui.cpp b/src/Main/MainGui.cpp
index 3216960f08..6602c52cec 100644
--- a/src/Main/MainGui.cpp
+++ b/src/Main/MainGui.cpp
@@ -42,7 +42,6 @@
 #include <QApplication>
 #include <QLocale>
 #include <QMessageBox>
-#include <QTextCodec>
 
 // FreeCAD header
 #include <App/Application.h>
@@ -96,20 +95,6 @@ private:
     FILE* file;
 };
 
-#if defined (FC_OS_LINUX) || defined(FC_OS_BSD)
-QString myDecoderFunc(const QByteArray &localFileName)
-{
-    QTextCodec* codec = QTextCodec::codecForName("UTF-8");
-    return codec->toUnicode(localFileName);
-}
-
-QByteArray myEncoderFunc(const QString &fileName)
-{
-    QTextCodec* codec = QTextCodec::codecForName("UTF-8");
-    return codec->fromUnicode(fileName);
-}
-#endif
-
 int main( int argc, char ** argv )
 {
 #if defined (FC_OS_LINUX) || defined(FC_OS_BSD)
diff --git a/src/Mod/TechDraw/Gui/QGSPage.cpp b/src/Mod/TechDraw/Gui/QGSPage.cpp
index d94c90ae79..356c7f7b66 100644
--- a/src/Mod/TechDraw/Gui/QGSPage.cpp
+++ b/src/Mod/TechDraw/Gui/QGSPage.cpp
@@ -40,7 +40,6 @@
 #include <QTextStream>
 #include <QFile>
 #include <QLabel>
-#include <QTextCodec>
 #include <cmath>
 #endif
 
diff --git a/src/Mod/TechDraw/Gui/QGVPage.cpp b/src/Mod/TechDraw/Gui/QGVPage.cpp
index 8d4312199d..0872cea1e3 100644
--- a/src/Mod/TechDraw/Gui/QGVPage.cpp
+++ b/src/Mod/TechDraw/Gui/QGVPage.cpp
@@ -43,7 +43,6 @@
 #include <QTextStream>
 #include <QFile>
 #include <QLabel>
-#include <QTextCodec>
 #endif
 
 #include <App/Application.h>