INISettingsInterface: Fix file leak on Linux

Author: stenzek

src/util/ini_settings_interface.cpp

@@ -19,31 +19,49 @@ Log_SetChannel(INISettingsInterface);
 #include <io.h> // _mktemp_s
 #else
 #include <stdlib.h> // mktemp
+#include <unistd.h>
 #endif
 
 // To prevent races between saving and loading settings, particularly with game settings,
 // we only allow one ini to be parsed at any point in time.
 static std::mutex s_ini_load_save_mutex;
 
-static std::string GetTemporaryFileName(const std::string& original_filename)
+static std::FILE* GetTemporaryFile(std::string* temporary_filename, const std::string& original_filename,
+                                   const char* mode, Error* error)
 {
-  std::string temporary_filename;
-  temporary_filename.reserve(original_filename.length() + 8);
-  temporary_filename.append(original_filename);
+  temporary_filename->clear();
+  temporary_filename->reserve(original_filename.length() + 8);
+  temporary_filename->append(original_filename);
 
 #ifdef _WIN32
-  temporary_filename.append(".XXXXXXX");
-  _mktemp_s(temporary_filename.data(), temporary_filename.length() + 1);
-#else
-  temporary_filename.append(".XXXXXX");
-#if defined(__linux__) || defined(__ANDROID__) || defined(__APPLE__)
-  mkstemp(temporary_filename.data());
+  temporary_filename->append(".XXXXXXX");
+  const errno_t err = _mktemp_s(temporary_filename->data(), temporary_filename->length() + 1);
+  if (err != 0)
+  {
+    Error::SetErrno(error, "_mktemp_s() failed: ", err);
+    return nullptr;
+  }
+
+  return FileSystem::OpenCFile(temporary_filename->c_str(), mode, error);
 #else
-  mktemp(temporary_filename.data());
-#endif
-#endif
+  temporary_filename->append(".XXXXXX");
+  const int fd = mkstemp(temporary_filename->data());
+  if (fd < 0)
+  {
+    Error::SetErrno(error, "mkstemp() failed: ", errno);
+    return nullptr;
+  }
+
+  std::FILE* fp = fdopen(fd, mode);
+  if (!fp)
+  {
+    Error::SetErrno(error, "mkstemp() failed: ", errno);
+    close(fd);
+    return nullptr;
+  }
 
-  return temporary_filename;
+  return fp;
+#endif
 }
 
 INISettingsInterface::INISettingsInterface(std::string filename) : m_filename(std::move(filename)), m_ini(true, true)
@@ -79,9 +97,9 @@ bool INISettingsInterface::Save(Error* error /* = nullptr */)
   }
 
   std::unique_lock lock(s_ini_load_save_mutex);
-  std::string temp_filename(GetTemporaryFileName(m_filename));
+  std::string temp_filename;
+  std::FILE* fp = GetTemporaryFile(&temp_filename, m_filename, "wb", error);
   SI_Error err = SI_FAIL;
-  std::FILE* fp = FileSystem::OpenCFile(temp_filename.c_str(), "wb", error);
   if (fp)
   {
     err = m_ini.SaveFile(fp, false);