Simplify log file handling

For cases where file logging is enabled then the framework simply uses the
specified path as is or defaults to the appdata directory on all
platforms. This has the advantage of moving it outside if the install
directory.

Framework/Kernel/src/ConfigService.cpp

@@ -382,88 +382,26 @@ void ConfigServiceImpl::registerLoggingFilterChannel(
  *
  */
 void ConfigServiceImpl::configureLogging() {
-  try {
-    // Ensure that the logging directory exists
-    m_logFilePath = getString("logging.channels.fileChannel.path");
-    Poco::Path logpath(m_logFilePath);
-
-    // Undocumented way to override the mantid.log path
-    if (Poco::Environment::has("MANTIDLOGPATH")) {
-      logpath = Poco::Path(Poco::Environment::get("MANTIDLOGPATH"));
-      logpath = logpath.absolute();
-      m_logFilePath = logpath.toString();
-    }
-
-    // An absolute path makes things simpler
+  // Undocumented way to override the mantid.log path
+  if (Poco::Environment::has("MANTIDLOGPATH")) {
+    auto logpath = Poco::Path(Poco::Environment::get("MANTIDLOGPATH"));
     logpath = logpath.absolute();
-
-    // First, try the logpath given
-    if (!m_logFilePath.empty()) {
-      try {
-        // Save it for later
-        m_logFilePath = logpath.toString();
-
-        // make this path point to the parent directory and create it if it does
-        // not exist
-        Poco::Path parent = logpath;
-        parent.makeParent();
-        Poco::File(parent).createDirectories();
-
-        // Try to create or append to the file. If it fails, use the default
-        FILE *fp = fopen(m_logFilePath.c_str(), "a+");
-        if (fp == nullptr) {
-          std::cerr
-              << "Error writing to log file path given in properties file: \""
-              << m_logFilePath << "\". Will use a default path instead.\n";
-          // Clear the path; this will make it use the default
-          m_logFilePath = "";
-        } else
-          fclose(fp);
-      } catch (std::exception &) {
-        std::cerr
-            << "Error writing to log file path given in properties file: \""
-            << m_logFilePath << "\". Will use a default path instead.\n";
-        // ERROR! Maybe the file is not writable!
-        // Clear the path; this will make it use the default
-        m_logFilePath = "";
-      }
-    }
-
-    // The path given was invalid somehow? Use a default
-    if (m_logFilePath.empty()) {
-      m_logFilePath = getUserPropertiesDir() + "mantid.log";
-      // Check whether the file can be written. The Poco::File::canWrite method
-      // does not work
-      // for files that don't exist, it throws an exception. It also can't be
-      // used to check for
-      // directory access as the Windows API doesn't return this information
-      // correctly for
-      // directories.
-      FILE *fp = fopen(m_logFilePath.c_str(), "a+");
-      if (!fp) {
-        // if we cannot write to the default directory then set use the system
-        // temp
-        logpath = Poco::Path::temp() + "mantid.log";
-        m_logFilePath = logpath.toString();
-        std::cerr << "Error writing to log file path to default location: \""
-                  << m_logFilePath
-                  << "\". Will use a system temp path instead: \""
-                  << m_logFilePath << "\"\n";
-      } else
-        fclose(fp);
-    }
+    m_logFilePath = logpath.toString();
     // Set the line in the configuration properties.
-    //  this'll be picked up by LoggingConfigurator (somehow)
     m_pConf->setString("logging.channels.fileChannel.path", m_logFilePath);
-
-    // make this path point to the parent directory and create it if it does not
-    // exist
-    logpath.makeParent();
-    if (!logpath.toString().empty()) {
-      Poco::File(logpath)
-          .createDirectories(); // Also creates all necessary directories
+  } else {
+    m_logFilePath = getString("logging.channels.fileChannel.path");
+    if (m_logFilePath.empty()) {
+      // Default to appdata/mantid.log
+      Poco::Path path(getAppDataDir());
+      path.append("mantid.log");
+      m_logFilePath = path.toString();
+      // Set the line in the configuration properties.
+      m_pConf->setString("logging.channels.fileChannel.path", m_logFilePath);
     }
+  }
 
+  try {
     // Configure the logging framework
     Poco::Util::LoggingConfigurator configurator;
     configurator.configure(m_pConf);
@@ -471,7 +409,6 @@ void ConfigServiceImpl::configureLogging() {
     std::cerr << "Trouble configuring the logging framework " << e.what()
               << '\n';
   }
-
   // register the filter channels - the order here is important
   registerLoggingFilterChannel("fileFilterChannel", nullptr);
   registerLoggingFilterChannel("consoleFilterChannel", nullptr);