[WAGON-584] LightweightHttpWagon and tests are built on false assumptions around internal buffering

[jira-importer]

Michael Osipov opened WAGON-584 and commented

The LightweightHttpWagon heavily differs from HttpWagon internally, the way HttpURLConnection is implemented it is virtually impossible to make them behave similar (or identical).

Notable differences:

• Expect Continue is virtually not supported and signals an exception as soon as non-2xx is received
• All content is buffered in a byte array making it extremely inefficient with large uploads
• As soon as streaming mode is enabled (see HttpURLConnection#setFixedLengthStreamingMode(long) and HttpURLConnection#setChunkedStreamingMode(int)) redirect and authentication support are disabled

Tests do assume that both behave the same although HttpWagon is fully streaming while the other one is not. So, the tests are illdesigned/based on false assumptions. Run branches WAGON-584_streaming/WAGON-584_streaming_no-expect-continue and see the failures.

This behavior is nowhere documented and not properly covered in tests.

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Affects: 3.3.4

Issue Links:

• WAGON-615 Deprecate Wagon HTTP Lightweight Provider

[jira-importer]

Michael Osipov commented

Still valid.

[slachiewicz]

Still open. Worth noting that the usual answer to this one — the provider is deprecated and goes away in 4.0.0 — does not currently dispose of it.

Wagon 4.0.0 has never been released: master is 4.0.0-M1-SNAPSHOT with no tag, the last release is 3.5.3, and the wagon-3.x branch is 3.5.4-SNAPSHOT and still active. So the deprecation points at a version nobody can run, and the 3.x line is expected to stay for the time being.

One thing does limit the blast radius: wagon-http-lightweight is not bundled in any Maven distribution. Maven 3.9.16, Maven 4.0.0-SNAPSHOT and Maven 4.1.0-SNAPSHOT all ship only wagon-provider-api, wagon-file, wagon-http and wagon-http-shared, all at 3.5.3. So this affects users who add the provider explicitly rather than anyone running a stock Maven.

That makes the original proposal — removing the provider rather than fixing the buffering — easier, not harder, but it is a decision for dev@ rather than something to leave implied by a site notice.

[slachiewicz]

Closing as Won't Fix in 3.x. The lightweight HTTP provider is fundamentally constrained by HttpURLConnection's internal buffering and lack of streaming redirect/auth support. The provider is deprecated (WAGON-615) and is not bundled with standard Maven distributions. It will be removed in 4.0.0.