Fix for ebean-gradle-plugin issue #43

[rob-bygrave]

Root Cause

The regression from 16.4.0 → 16.5.0+ is in ebean-agent, not the plugin code itself.

What changed: The new EbeanEnhanceTask (introduced via PR #41) captures sourceSet.output.classesDirs at Gradle configuration time (afterEvaluate). The Kotlin kapt plugin may not have registered its output directory — which contains META-INF/ebean-generated-info.mf — into classesDirs at that point. The old plugin (16.4.0) evaluated classesDirs inside a doLast hook at task execution time, when all kapt outputs were already registered.

Effect (chain of failures):

1. AgentManifest can't find ebean-generated-info.mf → entityPackages is empty
2. DetectQueryBean.isQueryBean("QRoleEntity") iterates empty entityPackages → returns false
3. AgentManifest.isDetectQueryBean("QRoleEntity") → false
4. EnhanceContext.isQueryBean() returns false immediately (the null-fallback is unreachable)
5. MethodAdapter does not replace GETFIELD permissions with _permissions()
6. Original Kotlin getter body runs → null-check on uninitialised lateinit field → UninitializedPropertyAccessException

Fix

File: ebean-agent/src/main/java/io/ebean/enhance/querybean/DetectQueryBean.java

Added an empty-packages fallback in isQueryBean(): when entityPackages is empty (manifest not found), trust naming convention alone — any class in a .../query/Q... or .../query/assoc/Q... package is treated as a query bean. This is consistent with FilterQueryBean.detectOnAll which already applies the same logic.

With the fix:

• manifest.isDetectQueryBean("QRoleEntity") → true (naming convention match)
• reader.get(true, owner, classLoader) reads bytes from enhancedDir
• classMeta.isQueryBean() → true (@TypeQueryBean annotation present)
• GETFIELD is replaced by _permissions() → enhancement works correctly