Fix bug that occasionally caused a call to be deleted twice

src/ruby/ext/grpc/rb_call.c

@@ -94,8 +94,13 @@ typedef struct grpc_rb_call {
 } grpc_rb_call;
 
 static void destroy_call(grpc_rb_call *call) {
+  /* Ensure that we only try to destroy the call once */
+  if (call->wrapped != NULL) {
     grpc_call_destroy(call->wrapped);
+    call->wrapped = NULL;
     grpc_rb_completion_queue_destroy(call->queue);
+    call->queue = NULL;
+  }
 }
 
 /* Destroys a Call. */

src/ruby/lib/grpc/generic/bidi_call.rb

@@ -161,7 +161,15 @@ module GRPC
         count += 1
         payload = @marshal.call(req)
         # Fails if status already received
+        begin
           @call.run_batch(SEND_MESSAGE => payload)
+        rescue GRPC::Core::CallError => e
+          # This is almost definitely caused by a status arriving while still
+          # writing. Don't re-throw the error
+          GRPC.logger.warn('bidi-write-loop: ended with error')
+          GRPC.logger.warn(e)
+          break
+        end
       end
       GRPC.logger.debug("bidi-write-loop: #{count} writes done")
       if is_client
@@ -173,14 +181,6 @@ module GRPC
         finished
       end
       GRPC.logger.debug('bidi-write-loop: finished')
-    rescue GRPC::Core::CallError => e
-      # This is almost definitely caused by a status arriving while still
-      # writing. Don't re-throw the error
-      GRPC.logger.warn('bidi-write-loop: ended with error')
-      GRPC.logger.warn(e)
-      notify_done
-      @writes_complete = true
-      finished
     rescue StandardError => e
       GRPC.logger.warn('bidi-write-loop: failed')
       GRPC.logger.warn(e)