Make Tycho work behind https proxy

[Bananeweizen]

If a proxy is specified with the https procotol in the settings.xml, Tycho fails downloading artifacts from any URL that uses that proxy, because it wrongly configures a SOCKS transport in such cases.

Fixes #1935, #2709, #2533.

This affects all 4.x versions and should probably be backported.

Fame belongs to @glatuske who had pointed me to that line some time earlier already...

[Bananeweizen]

The documentation probably also needs to be updated. In Tycho < 4.x it was sufficient to have a single https proxy entry in the settings.xml. It worked for both http and https URLs. With Tycho 4 it is mandatory to have one entry for http and one for https, even though that is typically the same proxy.

[github-actions]

Test Results

  576 files  ±0    576 suites  ±0   3h 44m 27s ⏱️ - 3m 23s
  380 tests ±0    371 ✅  - 2   6 💤 ±0  3 ❌ +2 
1 140 runs  ±0  1 118 ✅  - 2  19 💤 ±0  3 ❌ +2 

For more details on these failures, see this check.

Results for commit 9995887. ± Comparison against base commit 134f372.

[laeubi]

@Bananeweizen many thanks for this fix, regarding http/https I think if its not mandatory for plain maven we maybe should try to emulate it but in general I often see different proxy configs for http/https/socks so it does not seems to be much of an issue given that https should be preferred these days over http anyways.

Maybe it would be good to have a new "configuring proxys and mirrors" section here that explains some details regarding Tycho https://tycho.eclipseprojects.io/doc/latest/index.html

this can be done by adding a new item here: https://github.com/eclipse-tycho/tycho/tree/main/src/site

Beside that, I wish you a merry christmas 🎄

[github-actions]

💚 All backports created successfully

Status	Branch	Result
✅	tycho-4.0.x

Questions ?

Please refer to the Backport tool documentation and see the Github Action logs for details

[Bananeweizen]

It might work with a single entry, if the protocol is http (without s), because Maven will fall back to that entry for https: https://github.com/apache/maven-resolver/blob/bcb81f4286448e60fbc6ceb109adffafb21bd359/maven-resolver-util/src/main/java/org/eclipse/aether/util/repository/DefaultProxySelector.java#L82C1-L82C1.
Unfortunately, at least in our company basically everyone is using the https entry only, because that worked better with Tycho in the past.

I'll have a look at the documentation part, when there is some more spare time. Starting towards Christmas celebration now. Wish you a good time, too.