[Dev-luatex] Opening files in safer mode

Marcel Krüger tex at 2krueger.de
Tue Oct 23 23:28:40 CEST 2018


I think there is a bug in `io.open` in --safer mode:

      io.open(tex.jobname .. '.tex'):close()

If this document is run with `luatex --safer` it leads to `bad argument #1 to 'gsub' (string expected, got nil)`.

The problem is a missing `not` in luatex-core.lua, function luatex_io_open_readonly:
The default argument 'r' is used if an explicit argument is given and when no "how" argument
is given it tries to interpret the non existing argument.

This can be fixed by (I omit the changes to `luatex-core.c` in the diff, they are auto-generated anyway):

diff --git a/source/texk/web2c/luatexdir/lua/luatex-core.lua b/source/texk/web2c/luatexdir/lua/luatex-core.lua
index f2d55fd99..de7f12006 100644
--- a/source/texk/web2c/luatexdir/lua/luatex-core.lua
+++ b/source/texk/web2c/luatexdir/lua/luatex-core.lua
@@ -54,7 +54,7 @@ local function luatex_io_open(name,how)
 local function luatex_io_open_readonly(name,how)
-    if how then
+    if not how then
         how = 'r'
         how = gsub(how,'[^rb]','')

Best regards,
Marcel Krüger

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