fix #1557: readLines(textConnection()) may mangle characters in split…

…_lines()

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: knitr
 Type: Package
 Title: A General-Purpose Package for Dynamic Report Generation in R
-Version: 1.20.3
+Version: 1.20.4
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666")),
     person("Adam", "Vogt", role = "ctb"),

NEWS.md

@@ -12,6 +12,8 @@
 
 - The `sql` engine now caches the result properly when the chunk option `output.var` is specified (thanks, @yutannihilation, #1544).
 
+- `knit_params()` mangles UTF-8 text not representable in current locale (thanks, @kevinushey, #1557).
+
 # CHANGES IN knitr VERSION 1.20
 
 ## NEW FEATURES

R/utils.R

@@ -605,9 +605,8 @@ read_rforge = function(path, project, extra = '') {
 # because I think strsplit('', 'foo') should return '' instead of character(0)
 split_lines = function(x) {
   if (length(grep('\n', x)) == 0L) return(x)
-  con = textConnection(x)
-  on.exit(close(con))
-  readLines(con)
+  x[x == ''] = '\n'
+  unlist(strsplit(x, '\n'))
 }
 
 # if a string is encoded in UTF-8, convert it to native encoding

tests/testit/test-utils.R

@@ -141,6 +141,13 @@ assert(
   combine_words(c('a', 'b', 'c'), before = '``', after = "''") %==% "``a'', ``b'', and ``c''"
 )
 
+assert('split_lines() splits a character vector into lines by \\n', {
+  (split_lines('') %==% '')
+  (split_lines(NULL) %==% NULL)
+  (split_lines('a\nb') %==% c('a', 'b'))
+  (split_lines(c('a\nb', '', ' ', 'c')) %==% c('a', 'b', '', ' ', 'c'))
+})
+
 opts = list(fig.cap = 'Figure "caption" <>.', fig.lp = 'Fig:', label = 'foo')
 assert(
   '.img.cap() generates the figure caption and alt attribute',