Strange code introduced in changeset 7089

[Grzegorz Lukasik <hauserx@…>]

​http://code.djangoproject.com/changeset/7089

 	293	            try: 
 	294	                if nodelist.contains_nontext: 
 	295	                    raise AttributeError 
 	296	            except AttributeError: 
 	297	                raise TemplateSyntaxError("%r must be the first tag in the template." % node) 

raising exception and then catching it immediately doesn't look right.

[Malcolm Tredinnick]

The current code is correct. We need to catch the attribute error because nodelist might not have an attribute called contains_nontext (read the commit message for why that's the case). Therefore, to avoid code duplication, since we want the same error handling, we just make sure we leap into the exception catcher. This is all in the error path, so it's not a performance penalty that's paid by correct code. It's also fairly idiomatic Python: if a block of code has an exception handler and you need the same error handling, jump into the exception handling portion by raising the right exception. Used throughout the standard library in quite a few places.

So, thanks for the review, but it's correct.