Since rstudio#127, the callbacks registered using the websocket metho…

…d $onClose() are not run when async=FALSE. I don't understand why.

The same result could have been obtained with `on.exit(close_ws(), add = TRUE, after = FALSE)` but the `after` argument is quite recent (R 3.5.0), I prefer to avoid it for backward compatibility with R < 3.5.0.

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: pagedown
 Type: Package
 Title: Paginate the HTML Output of R Markdown with CSS for Print
-Version: 0.6.3
+Version: 0.6.4
 Authors@R: c(
   person("Yihui", "Xie", role = c("aut", "cre"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666")),
   person("Romain", "Lesur", role = c("aut", "cph"), comment = c(ORCID = "0000-0002-0721-5595")),

NEWS.md

@@ -8,6 +8,10 @@
 
 - Using RStudio, any R Markdown HTML output formats can be directly printed to PDF by adding the line `"knit: pagedown::chrome_print"` to the YAML header: this line modifies the behavior of the "Knit" button of RStudio and produce both HTML and PDF documents.
 
+## BUG FIXES
+
+- In `chrome_print()` with `async = FALSE`, the Chrome processus and the local web server are properly closed when the function exits. This regression was introduced in **pagedown** 0.6.
+
 # CHANGES IN pagedown VERSION 0.6
 
 ## MINOR CHANGES

R/chrome.R

@@ -177,7 +177,11 @@ chrome_print = function(
     }
 
     t0 = Sys.time(); token = new.env(parent = emptyenv())
-    on.exit(close_ws())
+    on.exit({
+      close_ws()
+      kill_chrome()
+      if (!is.null(svr)) stop_server()
+    })
     print_page(ws, url, output2, wait, verbose, token, format, options, selector, box_model, scale, res_fun, rej_fun)
 
     if (async) {