[CLucene-dev] Bug in SegmentMerger and IndexWriter

[Šplíchal J. <spl...@to...>]

Hello, 

please find attached TestIndexWriter.cpp extended with one more test that
shows two different bugs:
1) If you leave the test as it is, than it crashes on line 680 when optimizing an index that 
was previously empty (all documents were deleted) and then some documents has been added.
We were able to fix this bug, the problem is in SegmentMerger.cpp 769 where 
          reader->norms(fi->name, normBuffer.values);
is called with normBuffer.values == NULL.
To prevent this it is sufficient to initialize the normBuffer at the beginning of the method
with length 1.

2) If you uncomment writer->optimize(); on line 660 in the test, than the following call to 
writer->close(); crashes. We have not found any solution for this issue where we could be 
sure about all consequences. But the problematic method in this case is
bool IndexWriter::flushDocStores()
which intializes a local variable files by calling:
	const std::vector<std::string>& files = docWriter->files();
but the following calls have as side effect modification of this vector in such way
that the application crashes.

Best Regards, 
Jiri