RUBY-3898 Remove dead cursor-pinning block, fix cursor id for OP_MSG

lib/mongo/operation/result.rb

@@ -162,15 +162,6 @@ def acknowledged?
         !!@replies
       end
 
-      # Whether the result contains cursor_id
-      #
-      # @return [ true, false ] If the result contains cursor_id.
-      #
-      # @api private
-      def has_cursor_id?
-        acknowledged? && replies.last.respond_to?(:cursor_id)
-      end
-
       # Get the cursor id if the response is acknowledged.
       #
       # @note Cursor ids of 0 indicate there is no cursor on the server.
@@ -183,7 +174,17 @@ def has_cursor_id?
       # @since 2.0.0
       # @api private
       def cursor_id
-        acknowledged? ? replies.last.cursor_id : 0
+        return 0 unless acknowledged?
+
+        if replies.last.respond_to?(:cursor_id)
+          # Legacy OP_REPLY replies expose the cursor id directly.
+          replies.last.cursor_id
+        elsif first_document.key?(CURSOR)
+          # OP_MSG command replies carry the cursor id in the `cursor` subdocument.
+          first_document[CURSOR][CURSOR_ID] || 0
+        else
+          0
+        end
       end
 
       # Get the namespace of the cursor. The method should be defined in

lib/mongo/operation/shared/executable.rb

@@ -64,14 +64,6 @@ def do_execute(connection, context, options = {})
                     end
                   end
 
-                  if result.has_cursor_id? &&
-                     connection.description.load_balancer?
-                    if result.cursor_id == 0
-                      connection.unpin
-                    else
-                      connection.pin
-                    end
-                  end
                   process_result(result, connection)
                 end
               end

lib/mongo/tracing/open_telemetry/command_tracer.rb

@@ -206,9 +206,23 @@ def session_attributes(message)
         # @param _context [ OpenTelemetry::Context ] the context (unused).
         # @param span [ OpenTelemetry::Trace::Span ] the current span.
         def process_cursor_context(result, _cursor_id, _context, span)
-          return unless result.has_cursor_id? && result.cursor_id.positive?
+          cursor_id = normalize_cursor_id(result.cursor_id)
+          return unless cursor_id.positive?
 
-          span.set_attribute('db.mongodb.cursor_id', result.cursor_id)
+          span.set_attribute('db.mongodb.cursor_id', cursor_id)
+        end
+
+        # Normalizes a cursor id to a plain Integer.
+        #
+        # OP_MSG replies deserialized in :bson mode expose the cursor id as a
+        # BSON::Int64, which does not implement Numeric#positive? and is not a
+        # valid OpenTelemetry attribute type.
+        #
+        # @param cursor_id [ Integer | BSON::Int64 ] the raw cursor id.
+        #
+        # @return [ Integer ] the cursor id as an Integer.
+        def normalize_cursor_id(cursor_id)
+          cursor_id.is_a?(BSON::Int64) ? cursor_id.value : cursor_id
         end
 
         # Records error status code if the command failed.

spec/mongo/operation/result_spec.rb

@@ -83,22 +83,24 @@ def get_result(client)
         expect(result.cursor_id).to eq(0)
       end
     end
-  end
 
-  describe '#has_cursor_id?' do
-    context 'when the reply exists' do
-      let(:cursor_id) { 5 }
+    context 'when the reply is an OP_MSG carrying a cursor subdocument' do
+      let(:reply) do
+        Mongo::Protocol::Msg.new([], {}, { 'cursor' => { 'id' => 42 } })
+      end
 
-      it 'returns true' do
-        expect(result).to have_cursor_id
+      it 'reads the cursor id from the cursor subdocument' do
+        expect(result.cursor_id).to eq(42)
       end
     end
 
-    context 'when the reply does not exist' do
-      let(:reply) { nil }
+    context 'when the reply is an OP_MSG without a cursor subdocument' do
+      let(:reply) do
+        Mongo::Protocol::Msg.new([], {}, { 'ok' => 1 })
+      end
 
-      it 'returns false' do
-        expect(result).not_to have_cursor_id
+      it 'returns zero' do
+        expect(result.cursor_id).to eq(0)
       end
     end
   end

spec/mongo/tracing/open_telemetry/command_tracer_spec.rb

@@ -67,7 +67,7 @@
   describe '#trace_command' do
     let(:span) { instance_double(OpenTelemetry::Trace::Span, finish: nil, set_attribute: nil) }
     let(:context) { instance_double(Mongo::Operation::Context) }
-    let(:result) { instance_double(Mongo::Operation::Result, has_cursor_id?: false, successful?: true) }
+    let(:result) { instance_double(Mongo::Operation::Result, cursor_id: 0, successful?: true) }
 
     before do
       allow(otel_tracer).to receive(:start_span).and_return(span)
@@ -103,7 +103,7 @@
 
     context 'when result has cursor_id' do
       let(:result) do
-        instance_double(Mongo::Operation::Result, has_cursor_id?: true, cursor_id: 789, successful?: true)
+        instance_double(Mongo::Operation::Result, cursor_id: 789, successful?: true)
       end
 
       it 'sets the cursor_id attribute' do
@@ -112,9 +112,20 @@
       end
     end
 
+    context 'when result cursor_id is a BSON::Int64' do
+      let(:result) do
+        instance_double(Mongo::Operation::Result, cursor_id: BSON::Int64.new(789), successful?: true)
+      end
+
+      it 'records the cursor id as an Integer' do
+        expect(span).to receive(:set_attribute).with('db.mongodb.cursor_id', 789)
+        command_tracer.trace_command(message, operation_context, connection) { result }
+      end
+    end
+
     context 'when result has zero cursor_id' do
       let(:result) do
-        instance_double(Mongo::Operation::Result, has_cursor_id?: true, cursor_id: 0, successful?: true)
+        instance_double(Mongo::Operation::Result, cursor_id: 0, successful?: true)
       end
 
       it 'does not set the cursor_id attribute' do