Fix clang-tidy/gcc warings

kdiff3fileitemactionplugin/kdiff3fileitemaction.h

@@ -49,7 +49,7 @@ private Q_SLOTS:
 
 private:
    QList<QUrl> m_list;
-   QWidget* m_pParentWidget;
+   QWidget* m_pParentWidget = nullptr;
    //KFileItemListProperties m_fileItemInfos;
 };
 #endif

src/SourceData.h

@@ -116,7 +116,7 @@ class SourceData
     };
     FileData m_normalData;
     FileData m_lmppData;
-    QTextCodec* m_pEncoding;
+    QTextCodec* m_pEncoding = nullptr;
 };
 
 #endif // !SOURCEDATA_H

src/diff.h

@@ -258,7 +258,7 @@ class Diff3LineList : public std::list<Diff3Line>
     //TODO: Add safety guards to prevent list from getting too large. Same problem as with QLinkedList.
     int size() const
     {
-        if(std::list<Diff3Line>::size() > std::numeric_limits<int>::max())
+        if(std::list<Diff3Line>::size() > (size_t)std::numeric_limits<int>::max())//explicit cast to silence gcc
         {
             qCDebug(kdiffMain) << "Diff3Line: List too large. size=" << std::list<Diff3Line>::size();
             Q_ASSERT(false); //Unsupported size