signal 11 on get_docid while iterating postlists in PHP5

[Alessandro Pasotti]

I'm testing SVN clustering branch from PHP5.

While trying to iterate documents in order to delete them, I've got a sigfault.

The attached test case should reproduce the bug, the sigfault happens while trying to access the last document in the posting list.

[Alessandro Pasotti]

test case

[Olly Betts]

You're accessing $i->get_docid() after calling $i->next() but before checking !$i->equals($this->database->postlist_end(). It's not valid to call methods on an iterator which has reached the end of the sequence, since it then points to just AFTER the end of the iterated sequence, not the last element. See bold comments added below:

$onemore = false; $i = $this->database->postlist_begin(); print "First : " . $i->get_docid() . "\n"; print "Last : " . $this->database->get_lastdocid() . "\n"; while(!$i->equals($this->database->postlist_end())){

$this->delete_document($i->get_docid()); print("del : ".$i->get_docid() . "\n"); $i->next(); $onemore = true; print("next : " .$i->get_docid() . "\n"); This may be invalid

} if($onemore){

$this->delete_document($i->get_docid()); This WILL be invalid

}

[Alessandro Pasotti]

Yes, I see it was an error but a segfault is not a graceful exit, no way to implement range checks in the C++ code?