optional BOM trimming

2 files changed, 22 insertions, 1 deletions

diff --git a/mod/tex/context/third/rst/rst_parser.lua b/mod/tex/context/third/rst/rst_parser.lua
index 6aeeb7d..f5c9fbc 100644
--- a/mod/tex/context/third/rst/rst_parser.lua
+++ b/mod/tex/context/third/rst/rst_parser.lua
@@ -34,6 +34,7 @@ else
     rst             = require "rst_context"
 end
 
+rst.stripBOM      = false
 helpers.rst_debug = false
 
 local warn = function(str, ...)
@@ -1350,11 +1351,21 @@ local parser = P{
     table_header_hline = P"=",
 }
 
+local function strip_BOM (raw)
+    if raw:match"^\239\187\191" then
+        return raw:sub(4)
+    end
+    return raw
+end
+
 local function load_file (name)
     f = assert(io.open(name, "r"), "Not a file!")
     if not f then return 1 end
     local tmp = f:read("*all")
     f:close()
+    if rst.strip_BOM then
+        return strip_BOM(tmp)
+    end
     return tmp
 end
 
diff --git a/mod/tex/context/third/rst/t-rst.mkiv b/mod/tex/context/third/rst/t-rst.mkiv
index 0359335..0a3e25b 100644
--- a/mod/tex/context/third/rst/t-rst.mkiv
+++ b/mod/tex/context/third/rst/t-rst.mkiv
@@ -114,7 +114,17 @@
 %D
 %D \showsetup{typesetRSTfile}
 
-\def\typesetRSTfile#1{\ctxlua{thirddata.rst.do_rst_file("#1")}}
+\def\do_typesetRSTfile[#1]#2{%
+  \iffirstargument
+    \getparameters[RST][#1]%
+    \doifdefined{\RSTstripBOM}{\ctxlua{thirddata.rst.strip_BOM = "\RSTstripBOM"}}%
+  \fi
+  \ctxlua{thirddata.rst.do_rst_file("#2")}%
+}
+
+\def\typesetRSTfile{%
+  \dosingleempty\do_typesetRSTfile%
+}
 
 %D \subsection{Typesetting Inline Snippets}
 %D