Query parser throws raw strings as exceptions

[Richard Boulton]

At line 131 of the query parser, the query parser throws an plain std::string as an exception. This should probably be wrapped in a subclass of Xapian::Error, so that applications can catch all Xapian errors using "catch Xapian::Error".

One particular problem this causes is with the SWIG bindings, which catch only Xapian::Error subclasses. As a result, the message from a queryparser error is thrown away, and replaced with "unknown error in Xapian".

[Olly Betts]

Line 131 of queryparser/queryparser.cc

This is a hang over from when queryparser was just part of Omega. I meant to change this when the QueryParser API was overhauled, but obviously I didn't!

I guess it would be reasonable to fix this in 1.0.

[Richard Boulton]

I've added a catch() to the SWIG bindings so that they report the error string, rather than "unknown error in Xapian" for these errors. I agree that this should be fixed for 1.0 (at which point this catch() clause could be removed).

[Olly Betts]

I think we should anticipate how this will be fixed in 1.0 and make it so the exception string is something like:

"QueryParserError: " + str

instead of just:

str

That way user code in scripting languages won't need to change at all for this change in 1.0 (user C++ code will need to change slightly of course).

It would also be good to have a test for this in the smoketest for languages where it's possible (it probably isn't really for PHP4).

[Olly Betts]

Actually, the exception thrown is "const char *", not "std::string" so your change doesn't make any difference - an excellent demonstration of why we really should add test cases wherever possible!

I've fixed this and added the "QueryParserError: " prefix, and added a testcase for both PHP4 (turns out it is possible) and PHP5.

Equivalent tests for other languages would still be nice though.

[Olly Betts]

Now fixed in SVN HEAD.

[Olly Betts]

Fixed in 1.0.0 release.