[mod_ssi] update chunk after shell output redirect

chunkqueue_update_file() to update size of file chunk after
redirecting shell output to file fd

src/chunk.c

@@ -446,6 +446,12 @@ void chunkqueue_use_memory(chunkqueue * const restrict cq, chunk *ckpt, size_t l
     *(ckpt ? &ckpt->next : &cq->first) = NULL;
 }
 
+void chunkqueue_update_file(chunkqueue * const restrict cq, chunk *c, off_t len) {
+    /*assert(c->type == FILE_CHUNK);*/
+    c->file.length += len;
+    cq->bytes_in += len;
+}
+
 void chunkqueue_set_tempdirs_default (const array *tempdirs, off_t upload_temp_file_size) {
 	chunkqueue_default_tempdirs = tempdirs;
 	chunkqueue_default_tempfile_size

src/chunk.h

@@ -105,6 +105,7 @@ __attribute_returns_nonnull__
 char * chunkqueue_get_memory(chunkqueue * restrict cq, size_t * restrict len);
 /* commit len bytes of mem obtained from chunkqueue_get_memory() */
 void chunkqueue_use_memory(chunkqueue * restrict cq, chunk *ckpt, size_t len);
+void chunkqueue_update_file(chunkqueue * restrict cq, chunk *c, off_t len);
 
 /* mark first "len" bytes as written (incrementing chunk offsets)
  * and remove finished chunks

src/mod_ssi.c

@@ -816,7 +816,7 @@ static int process_ssi_stmt(request_st * const r, handler_ctx * const p, const c
 				log_error(errh, __FILE__, __LINE__, "process exited abnormally: %s", cmd);
 			}
 			if (0 == fstat(c->file.fd, &stb)) {
-				c->file.length = stb.st_size;
+				chunkqueue_update_file(cq, c, stb.st_size);
 			}
 		}