fix: escape "%" etc. in package_seealso_urls()

see r-lib#1415

R/object-package.R

@@ -1,15 +1,16 @@
 package_seealso <- function(URL, BugReports) {
   itemize("Useful links:", package_seealso_urls(URL, BugReports))
 }
+
 package_seealso_urls <- function(URL = NULL, BugReports = NULL) {
   if (!is.null(URL)) {
-    links <- paste0("\\url{", strsplit(URL, ",\\s+")[[1]], "}")
+    links <- paste0("\\url{", escape(strsplit(URL, ",\\s+")[[1]]), "}")
     links <- gsub("\\url\\{https://doi.org/", "\\doi{", links)
   } else {
     links <- character()
   }
   if (!is.null(BugReports)) {
-    links <- c(links, paste0("Report bugs at \\url{", BugReports, "}"))
+    links <- c(links, paste0("Report bugs at \\url{", escape(BugReports), "}"))
   }
 
   links