Catch C++ exceptions by const reference

Fixes #2277

api/logic/minecraft/Component.cpp

@@ -323,7 +323,7 @@ bool Component::customize()
 		m_metaVersion.reset();
 		emit dataChanged();
 	}
-	catch (Exception &error)
+	catch (const Exception &error)
 	{
 		qWarning() << "Version could not be loaded:" << error.cause();
 	}

api/logic/minecraft/ComponentList.cpp

@@ -195,7 +195,7 @@ static bool loadComponentList(ComponentList * parent, const QString & filename,
 			container.append(componentFromJsonV1(parent, componentJsonPattern, obj));
 		}
 	}
-	catch (JSONValidationError &err)
+	catch (const JSONValidationError &err)
 	{
 		qCritical() << "Couldn't parse" << componentsFile.fileName() << ": bad file format";
 		container.clear();
@@ -1150,7 +1150,7 @@ std::shared_ptr<LaunchProfile> ComponentList::getProfile() const
 			}
 			d->m_profile = profile;
 		}
-		catch (Exception & error)
+		catch (const Exception &error)
 		{
 			qWarning() << "Couldn't apply profile patches because: " << error.cause();
 		}

api/logic/minecraft/ProfileUtils.cpp

@@ -57,7 +57,7 @@ bool readOverrideOrders(QString path, PatchOrder &order)
 			order.append(Json::requireString(item));
 		}
 	}
-	catch (JSONValidationError &err)
+	catch (const JSONValidationError &err)
 	{
 		qCritical() << "Couldn't parse" << orderFile.fileName() << ": bad file format";
 		qWarning() << "Ignoring overriden order";
@@ -82,7 +82,7 @@ static VersionFilePtr guardedParseJson(const QJsonDocument & doc,const QString &
 	{
 		return OneSixVersionFormat::versionFileFromJson(doc, filepath, requireOrder);
 	}
-	catch (Exception & e)
+	catch (const Exception &e)
 	{
 		return createErrorVersionFile(fileId, filepath, e.cause());
 	}

api/logic/minecraft/World.cpp

@@ -263,13 +263,13 @@ static QString read_string (nbt::value& parent, const char * name, const QString
 		auto & tag_str = namedValue.as<nbt::tag_string>();
 		return QString::fromStdString(tag_str.get());
 	}
-	catch(std::out_of_range e)
+	catch (const std::out_of_range &e)
 	{
 		// fallback for old world formats
 		qWarning() << "String NBT tag" << name << "could not be found. Defaulting to" << fallback;
 		return fallback;
 	}
-	catch(std::bad_cast e)
+	catch (const std::bad_cast &e)
 	{
 		// type mismatch
 		qWarning() << "NBT tag" << name << "could not be converted to string. Defaulting to" << fallback;
@@ -289,13 +289,13 @@ static int64_t read_long (nbt::value& parent, const char * name, const int64_t &
 		auto & tag_str = namedValue.as<nbt::tag_long>();
 		return tag_str.get();
 	}
-	catch(std::out_of_range e)
+	catch (const std::out_of_range &e)
 	{
 		// fallback for old world formats
 		qWarning() << "Long NBT tag" << name << "could not be found. Defaulting to" << fallback;
 		return fallback;
 	}
-	catch(std::bad_cast e)
+	catch (const std::bad_cast &e)
 	{
 		// type mismatch
 		qWarning() << "NBT tag" << name << "could not be converted to long. Defaulting to" << fallback;
@@ -338,7 +338,7 @@ void World::loadFromLevelDat(QByteArray data)
 		qDebug() << "Last Played:" << m_lastPlayed.toString();
 		qDebug() << "Seed:" << m_randomSeed;
 	}
-	catch (nbt::io::input_error e)
+	catch (const nbt::io::input_error &e)
 	{
 		qWarning() << "Unable to load" << m_folderName << ":" << e.what();
 		is_valid = false;

api/logic/minecraft/forge/ForgeXzDownload.cpp

@@ -345,7 +345,7 @@ void ForgeXzDownload::decompressAndInstall()
 		// NOTE: this takes ownership of both FILE pointers. That's why we duplicate them above.
 		unpack_200(file_in, file_out);
 	}
-	catch (std::runtime_error &err)
+	catch (const std::runtime_error &err)
 	{
 		m_status = Job_Failed;
 		qCritical() << "Error unpacking " << pack200_file.fileName() << " : " << err.what();