Fix Clang-Tidy & Clazy 'bugprone-unhandled-self-assignment' warnings

Change-Id: I566b2caaddb3f1167c4579915af0c15dde836b73
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

3 files changed, 18 insertions, 0 deletions

diff --git a/src/lib/corelib/logging/logger.cpp b/src/lib/corelib/logging/logger.cpp
index d4020892f..d4f51cd30 100644
--- a/src/lib/corelib/logging/logger.cpp
+++ b/src/lib/corelib/logging/logger.cpp
@@ -79,6 +79,9 @@ LogWriter::~LogWriter()
 
 const LogWriter &LogWriter::operator=(const LogWriter &other)
 {
+    if (this == &other) // Self assignment guard.
+        return *this;
+
     m_logSink = other.m_logSink;
     m_level = other.m_level;
     m_message = other.m_message;
diff --git a/src/lib/corelib/parser/qmlerror.cpp b/src/lib/corelib/parser/qmlerror.cpp
index 157d1690f..d9fbdd703 100644
--- a/src/lib/corelib/parser/qmlerror.cpp
+++ b/src/lib/corelib/parser/qmlerror.cpp
@@ -114,6 +114,9 @@ QmlError::QmlError(const QmlError &other)
 */
 QmlError &QmlError::operator=(const QmlError &other)
 {
+    if (this == &other) // Self assignment guard.
+        return *this;
+
     if (!other.d) {
         delete d;
         d = nullptr;
diff --git a/src/shared/json/json.cpp b/src/shared/json/json.cpp
index ffd7cbe9a..eb27d6296 100644
--- a/src/shared/json/json.cpp
+++ b/src/shared/json/json.cpp
@@ -841,6 +841,9 @@ JsonValue::JsonValue(const JsonValue &other)
  */
 JsonValue &JsonValue::operator=(const JsonValue &other)
 {
+    if (this == &other) // Self assignment guard.
+        return *this;
+
     if (t == String && stringData && !stringData->ref.deref())
         delete stringData;
 
@@ -1310,6 +1313,9 @@ JsonArray::JsonArray(const JsonArray &other)
  */
 JsonArray &JsonArray::operator=(const JsonArray &other)
 {
+    if (this == &other) // Self assignment guard.
+        return *this;
+
     if (d != other.d) {
         if (d && !d->ref.deref())
             delete d;
@@ -2353,6 +2359,9 @@ JsonObject::JsonObject(const JsonObject &other)
  */
 JsonObject &JsonObject::operator=(const JsonObject &other)
 {
+    if (this == &other) // Self assignment guard.
+        return *this;
+
     if (d != other.d) {
         if (d && !d->ref.deref())
             delete d;
@@ -3305,6 +3314,9 @@ JsonDocument::JsonDocument(const JsonDocument &other)
  */
 JsonDocument &JsonDocument::operator=(const JsonDocument &other)
 {
+    if (this == &other) // Self assignment guard.
+        return *this;
+
     if (d != other.d) {
         if (d && !d->ref.deref())
             delete d;