Warn user and ignore *FilterChannel properties

This will allow users to have logging again

Framework/Kernel/src/ConfigService.cpp

@@ -325,6 +325,48 @@ void ConfigServiceImpl::setBaseDirectory() {
 #endif
 }
 
+namespace {
+// look for specific keys and throw an exception if one is found
+std::string checkForBadConfigOptions(const std::string &filename,
+                                     const std::string &propertiesString) {
+  std::stringstream stream(propertiesString);
+  std::stringstream resultPropertiesString;
+  std::string line;
+  int line_num = 0;
+  while (std::getline(stream, line)) {
+    line_num += 1; // increment early
+    bool is_ok = true;
+
+    // Check for common errors. Empty lines are ok, things that are a key
+    // without a value are a critical failure. Forbidden keys are just commented
+    // out.
+    if (line.empty() || (Kernel::Strings::strip(line)[0] == '#')) {
+      // do nothing
+    } else if (line.find("FilterChannel") != std::string::npos) {
+      is_ok = false;
+    }
+
+    // Print warning to error channel and comment out offending line
+    if (!is_ok) {
+      const auto end = line.find("=");
+      std::cerr << "Encontered invalid key \"";
+      if (end != std::string::npos) {
+        std::cerr << Kernel::Strings::strip(line.substr(0, end));
+      } else {
+        std::cerr << Kernel::Strings::strip(line);
+      }
+      std::cerr << "\" in " << filename << " on line " << line_num << std::endl;
+
+      // comment out the property
+      resultPropertiesString << '#';
+    }
+    // copy over the line
+    resultPropertiesString << line << '\n';
+  }
+  return resultPropertiesString.str();
+}
+} // end of anonymous namespace
+
 /** Loads the config file provided.
  *  If the file contains logging setup instructions then these will be used to
  *setup the logging framework.
@@ -358,6 +400,9 @@ void ConfigServiceImpl::loadConfig(const std::string &filename,
       }
     }
 
+    // verify the contents and comment out offending lines
+    temp = checkForBadConfigOptions(filename, temp);
+
     // store the property string
     if ((append) && (!m_PropertyString.empty())) {
       m_PropertyString = m_PropertyString + "\n" + temp;

Framework/Kernel/test/ConfigServiceTest.h

@@ -483,6 +483,7 @@ public:
     writer << "\n";
     writer << "mantid.thorax = 10\n";
     writer << "# This comment line\n";
+    writer << " # This is an indented comment line\n";
     writer << "key.withnospace=5\n";
     writer << "key.withnovalue";
     writer.close();
@@ -512,11 +513,12 @@ public:
     }
     reader.close();
 
-    TS_ASSERT_EQUALS(prop_lines.size(), 4);
+    TS_ASSERT_EQUALS(prop_lines.size(), 5);
     TS_ASSERT_EQUALS(prop_lines[0], "mantid.legs=6");
     TS_ASSERT_EQUALS(prop_lines[1], "");
     TS_ASSERT_EQUALS(prop_lines[2], "# This comment line");
-    TS_ASSERT_EQUALS(prop_lines[3], "key.withnospace=5");
+    TS_ASSERT_EQUALS(prop_lines[3], " # This is an indented comment line");
+    TS_ASSERT_EQUALS(prop_lines[4], "key.withnospace=5");
 
     // Clean up
     prop_file.remove();