NGX_ERROR: Nested In-Memory Subrequest Error in Nginx

This code snippet is a conditional statement that checks if a subrequest is in memory. \n\nIf the condition r->subrequest_in_memory is true (i.e., the subrequest is in memory), then the code block inside the if statement will be executed. \n\nInside the if block, it logs an error message using the ngx_log_error function with the NGX_LOG_ERR level. The error message includes the URI of the subrequest being processed. \n\nFinally, it returns NGX_ERROR to indicate that there was an error processing the nested in-memory subrequest.