1 files changed, 42 insertions, 1 deletions

diff --git a/python/google/protobuf/descriptor_pool.py b/python/google/protobuf/descriptor_pool.py
index cb7146b6..8983f76f 100644
--- a/python/google/protobuf/descriptor_pool.py
+++ b/python/google/protobuf/descriptor_pool.py
@@ -58,6 +58,7 @@ directly instead of this class.
 __author__ = 'matthewtoia@google.com (Matt Toia)'
 
 import collections
+import warnings
 
 from google.protobuf import descriptor
 from google.protobuf import descriptor_database
@@ -127,12 +128,38 @@ class DescriptorPool(object):
     self._service_descriptors = {}
     self._file_descriptors = {}
     self._toplevel_extensions = {}
+    # TODO(jieluo): Remove _file_desc_by_toplevel_extension after
+    # maybe year 2020 for compatibility issue (with 3.4.1 only).
+    self._file_desc_by_toplevel_extension = {}
     # We store extensions in two two-level mappings: The first key is the
     # descriptor of the message being extended, the second key is the extension
     # full name or its tag number.
     self._extensions_by_name = collections.defaultdict(dict)
     self._extensions_by_number = collections.defaultdict(dict)
 
+  def _CheckConflictRegister(self, desc):
+    """Check if the descriptor name conflicts with another of the same name.
+
+    Args:
+      desc: Descriptor of a message, enum, service or extension.
+    """
+    desc_name = desc.full_name
+    for register, descriptor_type in [
+        (self._descriptors, descriptor.Descriptor),
+        (self._enum_descriptors, descriptor.EnumDescriptor),
+        (self._service_descriptors, descriptor.ServiceDescriptor),
+        (self._toplevel_extensions, descriptor.FieldDescriptor)]:
+      if desc_name in register:
+        file_name = register[desc_name].file.name
+        if not isinstance(desc, descriptor_type) or (
+            file_name != desc.file.name):
+          warn_msg = ('Conflict register for file "' + desc.file.name +
+                      '": ' + desc_name +
+                      ' is already defined in file "' +
+                      file_name + '"')
+          warnings.warn(warn_msg, RuntimeWarning)
+        return
+
   def Add(self, file_desc_proto):
     """Adds the FileDescriptorProto and its types to this pool.
 
@@ -169,6 +196,8 @@ class DescriptorPool(object):
     if not isinstance(desc, descriptor.Descriptor):
       raise TypeError('Expected instance of descriptor.Descriptor.')
 
+    self._CheckConflictRegister(desc)
+
     self._descriptors[desc.full_name] = desc
     self._AddFileDescriptor(desc.file)
 
@@ -184,6 +213,7 @@ class DescriptorPool(object):
     if not isinstance(enum_desc, descriptor.EnumDescriptor):
       raise TypeError('Expected instance of descriptor.EnumDescriptor.')
 
+    self._CheckConflictRegister(enum_desc)
     self._enum_descriptors[enum_desc.full_name] = enum_desc
     self._AddFileDescriptor(enum_desc.file)
 
@@ -197,6 +227,7 @@ class DescriptorPool(object):
     if not isinstance(service_desc, descriptor.ServiceDescriptor):
       raise TypeError('Expected instance of descriptor.ServiceDescriptor.')
 
+    self._CheckConflictRegister(service_desc)
     self._service_descriptors[service_desc.full_name] = service_desc
 
   def AddExtensionDescriptor(self, extension):
@@ -216,6 +247,7 @@ class DescriptorPool(object):
       raise TypeError('Expected an extension descriptor.')
 
     if extension.extension_scope is None:
+      self._CheckConflictRegister(extension)
       self._toplevel_extensions[extension.full_name] = extension
 
     try:
@@ -252,6 +284,12 @@ class DescriptorPool(object):
     """
 
     self._AddFileDescriptor(file_desc)
+    # TODO(jieluo): This is a temporary solution for FieldDescriptor.file.
+    # FieldDescriptor.file is added in code gen. Remove this solution after
+    # maybe 2020 for compatibility reason (with 3.4.1 only).
+    for extension in file_desc.extensions_by_name.values():
+      self._file_desc_by_toplevel_extension[
+          extension.full_name] = file_desc
 
   def _AddFileDescriptor(self, file_desc):
     """Adds a FileDescriptor to the pool, non-recursively.
@@ -331,7 +369,7 @@ class DescriptorPool(object):
       pass
 
     try:
-      return self._toplevel_extensions[symbol].file
+      return self._file_desc_by_toplevel_extension[symbol]
     except KeyError:
       pass
 
@@ -680,6 +718,7 @@ class DescriptorPool(object):
         fields[field_index].containing_oneof = oneofs[oneof_index]
 
     scope[_PrefixWithDot(desc_name)] = desc
+    self._CheckConflictRegister(desc)
     self._descriptors[desc_name] = desc
     return desc
 
@@ -718,6 +757,7 @@ class DescriptorPool(object):
                                      containing_type=containing_type,
                                      options=_OptionsOrNone(enum_proto))
     scope['.%s' % enum_name] = desc
+    self._CheckConflictRegister(desc)
     self._enum_descriptors[enum_name] = desc
     return desc
 
@@ -914,6 +954,7 @@ class DescriptorPool(object):
                                         methods=methods,
                                         options=_OptionsOrNone(service_proto),
                                         file=file_desc)
+    self._CheckConflictRegister(desc)
     self._service_descriptors[service_name] = desc
     return desc