write-command: if writeErrors is non-empty, mark result as failed.

This will ensure we do not continue processing in the ordered bulk API
case. Otherwise, we could accidentially continue in the case of failure.

Author: Christian Hergert

src/mongoc/mongoc-write-command.c

@@ -937,6 +937,7 @@ _mongoc_write_result_merge (mongoc_write_result_t  *result,  /* IN */
 {
    const bson_value_t *value;
    bson_iter_t iter;
+   bson_iter_t citer;
    int32_t n_upserted = 0;
    int32_t affected = 0;
 
@@ -950,6 +951,13 @@ _mongoc_write_result_merge (mongoc_write_result_t  *result,  /* IN */
       affected = bson_iter_int32 (&iter);
    }
 
+   if (bson_iter_init_find (&iter, reply, "writeErrors") &&
+       BSON_ITER_HOLDS_ARRAY (&iter) &&
+       bson_iter_recurse (&iter, &citer) &&
+       bson_iter_next (&citer)) {
+      result->failed = true;
+   }
+
    switch (command->type) {
    case MONGOC_WRITE_COMMAND_INSERT:
       result->nInserted += affected;