Index: src/google/protobuf/message.cc
===================================================================
--- src/google/protobuf/message.cc	(revision 490)
+++ src/google/protobuf/message.cc	(working copy)
@@ -277,7 +277,8 @@
 void GeneratedMessageFactory::RegisterFile(
     const char* file, RegistrationFunc* registration_func) {
   if (!InsertIfNotPresent(&file_map_, file, registration_func)) {
-    GOOGLE_LOG(FATAL) << "File is already registered: " << file;
+  	registration_func(file);
+    //GOOGLE_LOG(FATAL) << "File is already registered: " << file;
   }
 }
 
@@ -292,7 +293,7 @@
   // the mutex.
   mutex_.AssertHeld();
   if (!InsertIfNotPresent(&type_map_, descriptor, prototype)) {
-    GOOGLE_LOG(DFATAL) << "Type is already registered: " << descriptor->full_name();
+    //GOOGLE_LOG(DFATAL) << "Type is already registered: " << descriptor->full_name();
   }
 }
 
Index: src/google/protobuf/descriptor_database.cc
===================================================================
--- src/google/protobuf/descriptor_database.cc	(revision 490)
+++ src/google/protobuf/descriptor_database.cc	(working copy)
@@ -309,7 +309,18 @@
     const void* encoded_file_descriptor, int size) {
   FileDescriptorProto file;
   if (file.ParseFromArray(encoded_file_descriptor, size)) {
+    std::pair<const void*, int> existing = index_.FindFile(file.name());
+    if (existing.first) {
+      if (existing.second == size && memcmp(existing.first, encoded_file_descriptor, size) == 0) {
+        // Contents match
+        return true;
+      }
+      else {
+        GOOGLE_LOG(ERROR) << "File descriptor " << file.name() << " is already registered, but descriptor contents are different";
+      }
+    }
     return index_.AddFile(file, make_pair(encoded_file_descriptor, size));
+
   } else {
     GOOGLE_LOG(ERROR) << "Invalid file descriptor data passed to "
                   "EncodedDescriptorDatabase::Add().";