[BUG] SelectorDataRefresh.refresh() NPE on null data / no-op on empty data (HTTP sync)

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Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
76/100
Issue type
Bug
Clarity
Clearly specified
Activity status
Quiet
Tech stack
java
Domain
backend

Research direction

Start at shenyu-sync-data-center/shenyu-sync-data-http/src/main/java/org/apache/shenyu/sync/data/http/refresh/SelectorDataRefresh.java:71-81 and compare its flow with PluginDataRefresh, which is identified as the correct pattern. Verify that null and empty selector data clear existing subscriptions without throwing, and that refreshSelectorDataAll runs before the empty check.

Written by the indexing model from the issue text.

Description

data-sync: http priority: high type: bug
  • Severity: High
  • Location:
    shenyu-sync-data-center/shenyu-sync-data-http/src/main/java/org/apache/shenyu/sync/data/http/refresh/SelectorDataRefresh.java:71-81

Description:
if (CollectionUtils.isEmpty(data)) { ...; data.forEach(pluginDataSubscriber::unSelectorSubscribe); pluginDataSubscriber.refreshSelectorDataAll(); }. CollectionUtils.isEmpty(null) returns true, so the branch is entered with data == null, then data.forEach(...) throws NullPointerException. If data is an empty list, forEach is a no-op (unsubscribe nothing) and the clear intent is not achieved. The ordering is also backwards (forEach before refreshSelectorDataAll). Compare PluginDataRefresh which correctly calls refreshPluginDataAll() first and returns before iterating.

Impact:
HTTP sync refresh with an empty/null selector group crashes the long-polling task (NPE) or silently leaves stale selectors in cache.

Suggested fix:
Move pluginDataSubscriber.refreshSelectorDataAll() to before the empty check, and return early when empty (same pattern as PluginDataRefresh).

Confidence: High


Identified during the 2026-08-02 deep re-scan; full list in docs/scan2-2026-08-02/00-consolidated-critical-high.md.

Dominant language
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