John_Ha wrote:If possible, try to get merge into the subject line ...
Done!
Good news! Merging in the opposite direction, seems to be working (for now, anyway).
John_Ha wrote:More thoughts. Reject all the changes in the first half of his document, and now try merge. Now merge with the original to pick up the first half changes.
Another excellent idea. I will get back to giving this a go, but I only have 9 days left to get this book sorted, and there's a heck of a lot to sort out still.
John_Ha wrote:What I cannot work out is whether it is the quantity of changes causing the problem; or whether just one or two changes are mangled and they cause the problem.
Create a simple two page test document. Make changes in it (ideally ask him to make the changes). Now try to merge the two documents - does it work? If so, your method is OK and it looks like a fault in the document.
I had been thinking along the same lines, but it never occured to me to try rejecting some of the changes first.
There's definitely an fatal error in the document, (according to the validator, anyway). I thought I could fix it manually, but the offsets it provides don't seem to match up with what I have.
John_Ha wrote:That being said, splitting both documents into, say, 4, should at least confine the problem to 1/4 and the other 3/4 should be OK. Test splitting with your 2 page test document.
John_Ha wrote:I am sure I don't need to say only work on copies - whatever else you do don't mangle the only originals

Some time ago, I learnt the hard way that it's always wise to keep backups, but it's sound advice nonetheless, and definitely worth mentioning, as you can never be too sure.
Many, many thanks for your help again.
As soon as I can find the time, I'll see if I can drill it down to one particular change. It might even benefit me to try that out now, as I'd had to merge an error into my (currently) working document.
John_Ha wrote:A quick thought. Isn't merge based on having two "normal documents with no changes" in them? You now merge them, which produces a document with changes, which you now accept/reject.
So do try accepting/rejecting all his changes in his document. Now merge it as a "normal document" with your document.
I think I might have confused the issue a bit here. For some reason I was never able to get Edit -> Changes -> Merge Document... to work correctly. I always god some kind of error stating that they couldn't be merged.
Although I do record the changes he makes, and manually OK them all first, I then use Edit -> Compare Documents, and then go through the Accept/Reject changes list. The second step shouldn't be necessary, but we went through a period of forgetting to enable the Record Changes facility, so some unrecorded changes have snuck through.
I thought I'd give a merge a go again, and Writer crashes during the merge, irrespective of the direction of the merge.