Broken links in various topics

Thanks for the issue and patch! This is really annoying. The documentation content is being migrated to new URLs, but I think it is ***supposed*** to have redirects. Obviously, this page doesn't.

Anyway... I think this is the page that was migrated:
https://www.drupal.org/docs/8/core/modules/block/overview
titled "Working with blocks". So I think the correct patch would be to replace the old URL with this one for the "Working with..." page. And I don't see anything on the custom block module page that was adapted into the text of this page, so I think we can just cut down to this one link. Thanks!

Also adding the translation needed tag to this issue (our first test of the new proposed process!)

Adding a related issue to create tests to verify all the other outside/documentation URLs in the User Guide.

See also #2824046-61: Plan for URLs for core modules documentation because these pages should have had redirects. [Even if they do get redirects, we should still update the URLs in the User Guide, I think.]

This looks like it's actually a typo in the link used in the guide. The page used in the guide is http://drupal.org/documentation/modules/blocks, but the page on d.o. is http://drupal.org/documentation/modules/block (which does not redirect to the appropriate place).

That said, since this is the D8 version of the guide, we should just link directly to the D8 page at https://www.drupal.org/docs/8/core/modules/block/overview like @jhodgdon mentions above.

Over on #2874508: Add tests for URLs in guide pages, I made a script to extract all URLs in all languages' source files, and a test that visits the URLs and checks that they have status 200 (OK).

12 URLs failed the test. So, I think we should repurpose this issue to fix all 13 of them, rather than having 13 separate issues. Adding the list of broken URLs to the issue summary.

I'm also going to add to the test to make sure the final URL was the same as the original, to detect successful redirects... more coming soon...

Quite a few more redirects -- mostly http to https. Adding these to the summary.

I looked in more detail and various of these URLs. I've moved some to the category of "fails but don't fix", and have figured out what we should do about some others. I haven't looked at all of them yet... there are a bunch of drupal.org links that, like the ones in the original issue summary here, we probably need to look at more carefully in context before just accepting the redirects...

Better script (see #2874508-6: Add tests for URLs in guide pages)... pasting output into issue summary.

Ah, just saw #9. I just need to modify my URL testing script so it counts % as a valid URL character. Now it doesn't flag the hu.wikipedia page as 404, and a couple of other URLs that apparently had % in them and got cut off by my script. Good catch! I'll commit the change to the script shortly on the other issue. Meanwhile, updating the issue summary here with the corrected list.

Balu: Will it cause you problems if I do a global search/replace, including HU language source, to fix the redirected URLs? I think the HU team is the most active, and I am not worried about any other languages, I think it will be easier to fix them all at the same time in one patch rather than making each language do the fixes separately.

That was the question. I will replace URLs in all files then!

Well. Some of those redirects went to drupal 7 pages... and some of the references we used to write pages have gone away..

So, I spent some time looking for better resources, and made a sed script that did better redirects, after first editing manually the block-concept and block-regions files to take out things that were no longer there.

Phew!

Here's the script, plus the patch for the manual edits... I'm going to look over the full results in an hour or two and then run the URL checker again to see if there are more redirects etc. needed. Then hopefully make a commit. But uploading this now so it doesn't get lost...

Balu: If you have a moment, please look over the HU edits in the manual patch -- they may not be quite right as I don't read/write HU but I think they are OK...

OK, the script worked pretty well. I had to do one minor edit, and then when I ran the URL checker script again, I found just a couple of hits that I fixed in another sed script. I'm going to go ahead and commit this, mark it fixed, and send out an alert to the translator list.