add = TRUE for on.exit()

> Always set add = TRUE when using on.exit(). If you don’t, each call to on.exit() will overwrite the previous exit handler. Even when only registering a single handler, it’s good practice to set add = TRUE so that you won’t get any unpleasant surprises if you later add more exit handlers.

https://adv-r.hadley.nz/functions.html#on-exit

R/SWORD_files.R

@@ -13,15 +13,15 @@ create_zip.character <- function(x, ...) {
 }
 create_zip.data.frame <- function(x, ...) {
     tmpdf <- tempfile(fileext = ".zip")
-    on.exit(file.remove(tmpdf))
+    on.exit(file.remove(tmpdf), add = TRUE)
     tmp <- tempfile(fileext = ".zip")
     save(x, file = tmpdf)
     stopifnot(!utils::zip(tmp, tmpdf))
     return(tmp)
 }
 create_zip.list <- function(x, ...) {
     tmpdf <- sapply(seq_along(x), tempfile(fileext = ".zip"))
-    on.exit(file.remove(tmpdf))
+    on.exit(file.remove(tmpdf), add = TRUE)
     mapply(x, tmpdf, function(x, f) save(x, file = f), SIMPLIFY = TRUE)
     tmp <- tempfile(fileext = ".zip")
     stopifnot(!utils::zip(tmp, tmpdf))