Fix crash when calling estimateSize() (f'up to #12139) (#5628)

Author: chrchr-github

lib/checkother.cpp

@@ -2887,7 +2887,8 @@ void CheckOther::checkRedundantCopy()
             if (fScope && fScope->bodyEnd && Token::Match(fScope->bodyEnd->tokAt(-3), "return %var% ;")) {
                 const Token* varTok = fScope->bodyEnd->tokAt(-2);
                 if (varTok->variable() && !varTok->variable()->isGlobal() &&
-                    (!varTok->variable()->type() || estimateSize(varTok->variable()->type(), mSettings, symbolDatabase) > 2 * mSettings->platform.sizeof_pointer))
+                    (!varTok->variable()->type() || !varTok->variable()->type()->classScope ||
+                     estimateSize(varTok->variable()->type(), mSettings, symbolDatabase) > 2 * mSettings->platform.sizeof_pointer))
                     redundantCopyError(startTok, startTok->str());
             }
         }

test/cfg/qt.cpp

@@ -580,3 +580,16 @@ namespace {
         Q_PROPERTY(QHash<QString, int> hash READ hash WRITE setHash)
     };
 }
+
+struct SEstimateSize {
+    inline const QString& get() const { return m; }
+    QString m;
+};
+
+class QString;
+
+void dontCrashEstimateSize(const SEstimateSize& s) {
+    // cppcheck-suppress redundantCopyLocalConst
+    QString q = s.get();
+    if (!q.isNull()) {}
+}