Merge of r4416: Fixed AIO error handling on FreeBSD. The aio_return() must be called regardless of the error returned by aio_error(). Not calling it resulted in various problems up to segmentation faults (as AIO events are level-triggered and were reported again and again). Additionally, in "aio sendfile" case r->blocked was incremented in case of error returned from ngx_file_aio_read(), thus causing request hangs.

--- a/src/http/ngx_http_copy_filter_module.c
+++ b/src/http/ngx_http_copy_filter_module.c
@@ -190,7 +190,7 @@ ngx_http_copy_filter(ngx_http_request_t 
 
             rc = n;
 
-            if (file->aio) {
+            if (rc == NGX_AGAIN) {
                 file->aio->data = r;
                 file->aio->handler = ngx_http_copy_aio_sendfile_event_handler;