Validate duplicate TLD functions during parsing

[sainadh777]

Summary

• detect duplicate TLD function names while the descriptor is parsed
• remove the later duplicate-name pass from TagLibraryInfoImpl
• add parser-level regression coverage and complete checked-in TODO 32.1

Rationale and impact

The TLD data model now rejects a duplicate as soon as the second function is added during parsing. This keeps descriptor validation with the parser, avoids constructing a partially invalid TaglibXml, and preserves the existing user-visible validation behavior with a message owned by the TLD descriptor package.

The change is limited to duplicate function-name validation. Valid tag libraries are unaffected.

Validation

All commands ran with Eclipse Temurin JDK 25 and Ant 1.10.15 in Linux. The complete suite used a native case-sensitive Linux filesystem rather than the macOS-backed bind mount.

• /opt/ant/bin/ant -Dbase.path=/tomcat-build-libs -Dtest.entry=org.apache.tomcat.util.descriptor.tld.TestTldParser test
  • BUILD SUCCESSFUL; 7 tests, 0 failures, 0 errors, 0 skipped
• /opt/ant/bin/ant -Dbase.path=/tomcat-build-libs -Dexecute.validate=true validate
  • BUILD SUCCESSFUL; Checkstyle 13.9.0 completed
• /opt/ant/bin/ant -Dbase.path=/tomcat-build-libs clean deploy
  • BUILD SUCCESSFUL
• /opt/ant/bin/ant -quiet -Dbase.path=/tomcat-build-libs test
  • BUILD SUCCESSFUL in 30m45s; 651 suites, 41,276 tests, 0 failures, 0 errors, 316 environment/feature skips
• generated-distribution runtime smoke test
  • startup.sh started Tomcat; GET / returned HTTP 200; shutdown.sh stopped Tomcat and the recorded PID exited cleanly

[sainadh777]

@markt-asf, could you please review this Jasper/TLD parsing change when you have a chance? I selected you because you recently maintained these exact paths and reviewed a comparable Jasper change. Thank you.