util.xml: Add an option to allow <?processing instructions?>
These should generally be safe to just ignore, which should be the
default behavior of Expat and LuaExpat
--- a/spec/util_xml_spec.lua Fri Feb 04 20:11:18 2022 +0100
+++ b/spec/util_xml_spec.lua Fri Feb 04 20:47:39 2022 +0100
@@ -42,6 +42,13 @@
assert.falsy(ok);
end);
+ it("should allow processing instructions if asked nicely", function()
+ local x = "<?xml-stylesheet href='make-fancy.xsl'?><foo/>";
+ local stanza = xml.parse(x, {allow_processing_instructions = true});
+ assert.truthy(stanza);
+ assert.are.equal(stanza.name, "foo");
+ end);
+
it("should allow an xml declaration", function()
local x = "<?xml version='1.0'?><foo/>";
local stanza = xml.parse(x);
--- a/util/xml.lua Fri Feb 04 20:11:18 2022 +0100
+++ b/util/xml.lua Fri Feb 04 20:47:39 2022 +0100
@@ -72,11 +72,14 @@
end
end
handler.StartDoctypeDecl = restricted_handler;
- handler.ProcessingInstruction = restricted_handler;
if not options or not options.allow_comments then
-- NOTE: comments are generally harmless and can be useful when parsing configuration files or other data, even user-provided data
handler.Comment = restricted_handler;
end
+ if not options or not options.allow_processing_instructions then
+ -- Processing instructions should generally be safe to just ignore
+ handler.ProcessingInstruction = restricted_handler;
+ end
local parser = lxp.new(handler, ns_separator);
local ok, err, line, col = parser:parse(xml);
if ok then ok, err, line, col = parser:parse(); end