Indexing fails on a repository having commits with null email addresses.
Steps to Reproduce
This issue has been reproduced on repositories that are imported from SVN in which some of the emails are missing.
This issue has also been reproduced manually setting "email" field into null in cwd_user table.
When there is a case of commits with null email addresses, indexing should be working
Indexing fails with below exception in atlassian_bitbucket.log due to null email address
2020-01-22 15:26:26,330 WARN [commit-indexing:thread-4] c.a.s.i.i.DefaultCommitIndexingService Commit indexer com.atlassian.bitbucket.JiraKeyIndexer caused an error 'com.google.common.util.concurrent.UncheckedExecutionException: java.lang.NullPointerException: email' and has been disabled for the remainder of this indexing run. Enable debug logging to see the exception details.
2020-01-22 15:26:26,331 DEBUG [commit-indexing:thread-4] c.a.s.i.i.DefaultCommitIndexingService Commit indexer error:
com.google.common.util.concurrent.UncheckedExecutionException: java.lang.NullPointerException: email
java.lang.Thread.run(Thread.java:748) ... 1 frame trimmed2020-01-22 15:26:26,387 DEBUG [commit-indexing:thread-4] c.a.s.i.i.DefaultCommitIndexingService [SW_UGW/feed_router] Indexed 500 commits2020-01-22 15:26:26,388 ERROR [commit-indexing:thread-4] c.a.s.internal.idx.HierarchyIndexer [SW_UGW/feed_router] Indexing failedorg.springframework.transaction.UnexpectedRollbackException: Transaction rolled back because it has been marked as rollback-only at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:728) at com.atlassian.stash.internal.util.TransactionBatcher.commit(TransactionBatcher.java:90) at com.atlassian.stash.internal.util.TransactionBatcher.tick(TransactionBatcher.java:63) at