[XML-SIG] Support for Validating Parsers

[Lars Marius Garshol]

* Lars Marius Garshol
|
| I have one that can read ESIS from files, SP and SP -wxml, but it
| can't handle error messages properly on Win32. I think the problem
| is caused by SP doing something strange to emulate stderr on Win32
| where this doesn't exist at all.

* David Niergarth
| 
| Are you "handling" the errors or ignoring the errors? 

Both, in a sense. I want to detect them and report them to the SAX
ErrorHandler. The problem is that I need to interleave them with the
other callback events. Ignoring them is a only last resort on Win32 if
all else fails (or possibly reporting them after all the data events).

| If you have parsing errors (as opposed to warnings) seems like you'd
| usually need/want to fix them first, then make esis again.

Of course, but this is something the user must deal with after getting
the error messages from his/her application through the SAX driver.
 
| I don't know a way to suppress errors (like -s).

Well, I don't really want to suppress the errors, since the
ErrorHandler should be told about them.
 
What I want is for them to appear interleaved in the normal ESIS
stream as they do when nsgmls is run from the command line. However,
os.popen fails to accomplish this, instead the errors are still
printed to the console, while everything else is forwarded to my SAX
driver.

--Lars M.