LMX bug: Adium ticket #13628

[Evan Schoenberg, M.D.]

On Apr 26, 2010, at 8:15 PM, David Smith wrote:

> On Apr 26, 2010, at 5:47 PM, Evan Schoenberg, M.D. wrote:
> 
>> So LMX is supposed to be able to take data in chunks, from the end of the file.  It turns out that this doesn't work if a chunk breaks up an entity, though.
>> 
>> A chat transcript, submitted by lhirlimann to me via email by request, exhibits this behavior on my machine, when read by -[DCMessageContextDisplayPlugin contextForChat:], since that method reads in 4*getpagesize() byte chunks and that number of bytes from the end is the middle of an entity.
>> 
>> Specifically, the resulting chunk #1 starts with 'apos'.  The resulting chunk #2 ends with '&'.
>> 
>> The result is an assertion failure:
>> *** Assertion failure in -[LMXParser parseEntityReference:], /Volumes/Huffman/Projects/lmx-sholt/LMXParser.m:605
>> "entity name was empty! currentIndex is 5193 (&) out of 21579 bytes"
>> 
>> It's not clear to me how to proceed with a fix.  Do you (yes, you!) have any ideas?
>> 
>> I don't want to post the user's chat log to a public mailing list; if you're an existing developer and would like it in order to easily see the behavior, email me off-list.
>> 
>> This took way too long to hunt down, though it's a fairly obvious problem in retrospect.
>> 
>> Cheers,
>> Evan
> 
> Silly hackish fix: @try { thing that throws assertion failure } @catch (...) { read a few more bytes so we're not in mid-entity and try again }

Better than my @try and (@)fail, though also more complex.  Can you implement it? :)

-Evan