fix #913: remove non-printable characters in search_index.json (which are not searchable anyway and lead to invalid JSON)

Author: yihui

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: bookdown
 Type: Package
 Title: Authoring Books and Technical Documents with R Markdown
-Version: 0.20.1
+Version: 0.20.2
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666")),
     person("JJ", "Allaire", role = "ctb"),

NEWS.md

@@ -1,5 +1,9 @@
 # CHANGES IN bookdown VERSION 0.21
 
+## BUG FIXES
+
+- Make sure `search_index.json` contains valid characters for the JSON format (thanks, @wlandau, #913).
+
 ## MINOR CHANGES
 
 - The `--file-scope` behavior introduced in bookdown v0.20 is now disabled by default. This is due to broken TOC links for duplicate section names (e.g., "Exercises"; see #909) that have automatically generated identifiers.

R/gitbook.R

@@ -79,6 +79,7 @@ write_search_data = function() {
   x = matrix(strip_search_text(x), nrow = 3)
   x = apply(x, 2, xfun::json_vector, to_array = TRUE)
   x = paste0('[\n', paste0(x, collapse = ',\n'), '\n]')
+  x = gsub('[^[:print:]]', '', x)
   write_utf8(x, output_path('search_index.json'))
 }