CAMEL-23698: Do not append trailing ? to URI when query string is empty

[davsclaus]

Summary

• Fix URISupport.createURIWithQuery() to not append a bare ? when the query string is empty
• When camel-rest-openapi produces a REST call from an OpenAPI spec with optional query parameters that are not set, the URL ended with a trailing ? (e.g., /users/myuser/repos? instead of /users/myuser/repos)
• Some HTTP servers and proxies treat /resource and /resource? differently, so this can cause issues

Root Cause

URISupport.createURIWithQuery() checked if (query != null) before appending ? + query, but did not check if the query string was empty. Changed to if (query != null && !query.isEmpty()).

Test plan

• Added testCreateURIWithQueryEmptyQueryString in URISupportTest verifying no trailing ? is appended for empty query strings
• Existing URISupportTest tests pass (null query and non-empty query cases)

Claude Code on behalf of Claus Ibsen

[github-actions]

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🧪 CI tested the following changed modules:

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[davsclaus]

Reviewed — looks good to merge.

• The !query.isEmpty() guard on createURIWithQuery() is the right fix. The original null-only check (from 2011) never handled empty strings, but camel-rest-openapi can produce them when all optional query params are unset.
• Checked all 6 production callers (URISupport, ResourceHelper, HttpProducer, HttpHelper, NettyHttpHelper, UndertowHelper) — none rely on appending a bare ? for empty queries. They all benefit from this fix.
• Test coverage is appropriate: the new test complements the existing null and non-empty cases.
• No regression risk.

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