Restoring tabs after a crash (Chrome for Windows)

This is a solution for current versions of Chrome on Windows if you get the message "Restore pages? Chrome didn't shut down correctly" and either you click "X" instead of "Restore", or something else doesn't work. And you try ctrl-shift-T, but there are no closed tabs to reopen.

This just happened to me, and I went googling, and found this thread https://www.reddit.com/r/chrome/comments/11xlt58/i_cant_reopen_a_window_full_of_tabs_that_i_closed/?rdt=37545, which is now archived, so I can't reply there (nobody identified a solution in that thread). Apologies if there are now many other posts showing how to do this and this is the N+1th, but I didn't see one with a quick look at recent thread titles.

I've now worked out how to fix it, so I'm recording that here, partly for everyone else but also partly for "future me"...

1. When this happens, I think it's probably best to keep Chrome open. This is because if you close Chrome and open it again, you will be screwed, as you can only go "back in time" for one launch of Chrome with this method. If you close Chrome you are still OK, but if you get distracted for any reason and click on a link in an e-mail or another application and that opens Chrome, you will then have blown it.
2. You are now going to do some tweaking of files. You can either do this from a command prompt, or from the File Explorer. I'm not going to explain how to copy and rename files, or go into protected system directories, or display hidden files in the command prompt window, so make sure you know how to do all that.
3. Go into C:\Users\<yourname>\AppData\Local\Google\Chrome\User Data\Default.
4. Find the "Session" folder. Make a copy of it to "Session.copy" or any other name you like. This just gives you an extra chance to go back.
5. Go into the "Settings" folder. You should see two files called something like Session_1357645573839552. If you sort these by date, the older one, which I will call Session_xxxx, will be bigger, possibly over 1 MB, and the newer one, which I will call Session_yyyy, will be smaller, possibly less than 10 KB.
6. Rename the newer file (Session_yyyy) by adding ".ignore" (or anything you like) to the end of its name.
7. Rename the older file (Session_xxxx) to Session_yyyy.
8. You should now have two files, Session_yyyy and Session_yyyy.ignore.
9. Kill Chrome with Task Manager.
10. Restart Chrome. With a bit of luck, your tabs will return.

I don't know how the versions of Chrome for other platforms work, but maybe there is an analogous fix for them too.

I hope this will be useful for someone!