Translation files import not working properly when installing dev version

The same happens when you install a dev version. Somewhere (dont recall where) you can see which po file is loaded. The filename for the next (not yet existing) version is taken.

@alexpott came across this (or #2 at least) in #2614824: Tests fail when version constant is stable. According to @alexpott, the installer is looking for drupal-8.2.x.fr.po but it is actually drupal-8.2.0-dev.fr.po. Not sure if the OP was due to the same underlying bug or a different one (it's not entirely clear to me).

@johnv did you install using Drush?

So the early installer translation downloading and import is not using the same fallback strategy as the regular translation downloading and import. This results in problems for the non-interactive installer - probably because of caching somewhere. However they should use the same fallback strategy so we don't create unnecessary files.

The patch attached reverts #2614824: Tests fail when version constant is stable to hopefully shown that will the fix in #6 applied Drupal\node\Tests\NodeTypeTranslationTest will always fail.

The fix in #6 makes sense. It is indeed unfortunate that we don't use the same fallback code. It would be nice to open an issue about it and reference in the @todo.

Discussed the need to have code available to the installer and translation system with @dawehner - especially in relation to #2677532: Move drupal_check_incompatibility() functionality to a new Dependency class and Version component. We agreed that we should have an ExtensionVersioning component that can handle these sorts of things. It is a component because it should not have outside dependencies. It just a place to encapsulate all of our Drupal rules for manipulating version strings and checking them.

Tagging with random test failures as contrib tests might have the same issue as exposed by #2614824: Tests fail when version constant is stable it might look very random to them. This patch will make the behaviour consistent.

Okay interesting - can't simplify the logic in locale_translation_build_projects()

@alexpott, to answer your question #5 to clarify my statement #2: I do not do drush. I download a Drupal version via website, and install with Acquia Dev Desktop 2.0.

xmj in #4 confirms and specifies my finding.

The patches handle only dev versions. OP complains about the RC2-version, too.
Shouldn't the patch be amended with RC, ALFA and BETA suffixes?

@johnv in #4 @xjm is just repeating what I told her :) and that was about the -dev issue :). Thanks for answering the question about Drush.

I'll test with an RC version number and see what happens.

@johnv also I do not know how acquia dev desktop works - does it install the site or do you actually use the Drupal 8 installer? Because I suspect there is a difference between interactive and non-interactive install.

+++ b/core/includes/install.core.inc
@@ -5,6 +5,7 @@
@@ -1415,7 +1416,7 @@ function _install_get_version_info($version) {

In an ideal world this function would also live inside the ExtensionVersioning namespace and would be tested. We change the behaviour here ...

@johnv I can't repeat your precise issue...
Steps I've done:

1. Edited \Drupal to have const VERSION = '8.2.0-rc1';
2. Installed standard in English (using drush - which should not matter)
3. Installed locale and language via drush
4. Used the UI to add the German language - it went add did it's importing as expected.
5. Went to admin/config/regional/translate and searched for "Above the preview" it found
   
6. Went to de/admin/structure/views/settings and found the text translated
   

I think we should repurpose this issue to solve the early installer problem as the original issue reported is very similar but no longer appears to occur so perhaps we fixed it.

For both Drush and manual install I was able to replicate the original issue.
Tested with 8.1.x-dev which results in drupal-8.1.x.de.po. The string appears both in the .po file, de/admin/structure/views/settings and admin/config/regional/translate.
8.1.1 results in drupal-8.1.1.de.po. The string appears both in the .po file, de/admin/structure/views/settings and admin/config/regional/translate.

@nonsie, I repeated same steps on #23(except I checked out tag 8.2.0-rc1) and can't reproduce the issue. Also compared drupal-8.2.0-rc1.de.po vs drupal-8.1.1.de.po and can't find any difference related to string "Above the preview". Could you check against 8.2.0-rc1 and update if you still facing the issue?

Well, the theory was that #2113955: Rely on proper server side version fallback for translations fixed the dev version mapping once and for all.

As per @alexpott in #6:

So the early installer translation downloading and import is not using the same fallback strategy as the regular translation downloading and import. This results in problems for the non-interactive installer - probably because of caching somewhere. However they should use the same fallback strategy so we don't create unnecessary files.

This is still a possibility. @vijaycs85 did you check with drush to reproduce?

I can reproduce it with composer install - when you install dev version or specific commit then no information exists in info.yml
It makes translation check/update to skip this modules

Probably it needs some changes in d-org packaging