[Xapian-discuss] Re: queryparser dies badly on double search words.

[Olly Betts]

On Mon, Aug 22, 2005 at 06:18:53PM +0200, R. Mattes wrote:
> Well, i did some more testing and it seems that these malformed query
> strings trigger an exception that can only be cought by
>  catch (...) { 
> Hmm, looking at the sources in xapian-core/queryparser it _seems_ like
> the parser would only throw an exception of type (char *) but a handler
> like: catch(char *mesg) doesn't catch that exception

The exception type thrown is "const char *", which won't be caught by a
handler for "char *".  If you use "catch (const char *mesg)" instead it
should be caught.

This is a bug in the XS glue - it should be catching this exception.
(Untested) patch attached.

We probably shouldn't be throwing naked "const char *" either - it would
be more in keeping with the rest of the API to throw
Xapian::QueryParserException or similar.

> i wonder whether qeryparser throws internal->errmsg while it's still
> at it's initial value of NULL ...

In C++, NULL isn't a special type (unlike some other languages).
Throwing a pointer which has been assigned the value NULL will still
throw an exception of the type of the pointer.

Cheers,
    Olly
-------------- next part --------------
Index: XS/QueryParser.xs
===================================================================
--- XS/QueryParser.xs	(revision 30)
+++ XS/QueryParser.xs	(working copy)
@@ -50,8 +50,13 @@
 QueryParser::parse_query(q)
     string q
     CODE:
-	RETVAL = new Query();
-	*RETVAL = THIS->parse_query(q);
+	try {
+	    RETVAL = new Query();
+	    *RETVAL = THIS->parse_query(q);
+	}
+	catch (const char * err_msg) {
+	    croak( "Exception: %s", err_msg );
+	}
     OUTPUT:
 	RETVAL