Fix cjson leaks in Settings.cpp

Author: benbuck

CMakeLists.txt

@@ -97,6 +97,7 @@ add_executable(Finestray WIN32
     src/Bitmap.h
     src/BitmapHandleWrapper.h
     src/BrushHandleWrapper.h
+    src/CJsonWrapper.h
     src/COMLibraryWrapper.h
     src/ContextMenu.cpp
     src/ContextMenu.h

src/CJsonWrapper.h

@@ -0,0 +1,50 @@
+// Copyright 2020 Benbuck Nason
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+// cJSON
+#include <cJSON.h>
+
+// Standard library
+#include <string>
+
+class CJsonWrapper
+{
+public:
+    explicit CJsonWrapper(cJSON * cjson)
+        : cjson_(cjson)
+    {
+    }
+
+    ~CJsonWrapper()
+    {
+        if (cjson_) {
+            cJSON_Delete(cjson_);
+        }
+    }
+
+    operator cJSON *() const { return cjson_; }
+
+    std::string print()
+    {
+        char * rawJson = cJSON_Print(cjson_);
+        std::string json(rawJson);
+        free(rawJson);
+        return json;
+    }
+
+private:
+    cJSON * cjson_ {};
+};

src/Settings.cpp

@@ -16,15 +16,13 @@
 
 // App
 #include "AppName.h"
+#include "CJsonWrapper.h"
 #include "File.h"
 #include "Hotkey.h"
 #include "Log.h"
 #include "Path.h"
 #include "StringUtility.h"
 
-// cJSON
-#include <cJSON.h>
-
 // Windows
 #include <Windows.h>
 #include <shellapi.h>
@@ -250,13 +248,13 @@ void Settings::addAutoTray(const std::string & executable, const std::string & w
 
 bool Settings::parseJson(const std::string & json)
 {
-    const cJSON * cjson = cJSON_Parse(json.c_str());
+    CJsonWrapper cjson(cJSON_Parse(json.c_str()));
     if (!cjson) {
         WARNING_PRINTF("failed to parse settings JSON:\n%s\n", cJSON_GetErrorPtr());
         return false;
     }
 
-    DEBUG_PRINTF("parsed settings JSON:\n%s\n", cJSON_Print(cjson));
+    DEBUG_PRINTF("parsed settings JSON:\n%s\n", cjson.print().c_str());
 
     startWithWindows_ = getBool(cjson, settingKeys_[SK_StartWithWindows], startWithWindows_);
     showWindowsInMenu_ = getBool(cjson, settingKeys_[SK_ShowWindowsInMenu], showWindowsInMenu_);
@@ -300,7 +298,7 @@ bool Settings::fileExists(const std::string & fileName)
 
 std::string Settings::constructJSON()
 {
-    cJSON * cjson = cJSON_CreateObject();
+    CJsonWrapper cjson(cJSON_CreateObject());
     if (!cjson) {
         WARNING_PRINTF("failed to create settings JSON object\n");
         return std::string();
@@ -385,11 +383,10 @@ std::string Settings::constructJSON()
 
     if (fail) {
         WARNING_PRINTF("failed to construct json settings\n");
-        cJSON_Delete(cjson);
         return std::string();
     }
 
-    return cJSON_Print(cjson);
+    return cjson.print();
 }
 
 bool Settings::autoTrayItemCallback(const cJSON * cjson, void * userData)