interrupt the progress bar on error by adding \n (to stderr) so that the error message can be displayed on a new line (#2387)

Author: yihui

R/output.R

@@ -311,7 +311,10 @@ process_file = function(text, output) {
     res[i] = xfun:::handle_error(
       withCallingHandlers(
         if (tangle) process_tangle(group) else process_group(group),
-        error = function(e) if (xfun::pkg_available('rlang', '1.0.0')) rlang::entrace(e)
+        error = function(e) {
+          if (progress && is.function(pb$interrupt)) pb$interrupt()
+          if (xfun::pkg_available('rlang', '1.0.0')) rlang::entrace(e)
+        }
       ),
       function(loc) {
         setwd(wd)

R/utils.R

@@ -1136,6 +1136,7 @@ txt_pb = function(total, labels) {
       setTxtProgressBar(pb, i)
       cat_line(s[i])  # append chunk label to the progress bar
     },
+    interrupt = function() message('\n'),
     done = function() {
       # wipe the progress bar
       cat_line('\r', strrep(' ', max(w2, 10) + 10 + n))