Changing a mistyped letter from lower to upper case in a link fails update in MySQL

If you misspell a link and the corret it just by changing the case, a java.sql.BatchUpdateException: Duplicate entry occurs.
After this, the link must be removed from the page, page saved, and then added corretly afterwards.

Steps to reproduce:

1. Go to the Sandbox.
2. Create a page with name BugTest with parent Sandbox.WebHome
3. Just type in some text in the page and save.
4. Create a new page with name LinkBugTest with parent Sandbox.WebHome
5. In wiki edit mode, enter (note the deliberate lower case t in the link:
This page links to [BugTest>Bugtest.WebHome]

6. Save & View, you will notice the question mark indicating a missing page.
7. Edit the page again, correct to
This page links to [BugTest>BugTest.WebHome]
8. Save & View: KABOOM

A problem occured while trying to service your request. Please contact the support if this happens again.

Detailed information:
Error number 3201 in 3: Exception while saving document Sandbox.LinkBugTest
Wrapped Exception: Could not execute JDBC batch update
com.xpn.xwiki.XWikiException: Error number 3201 in 3: Exception while saving document Sandbox.LinkBugTest
Wrapped Exception: Could not execute JDBC batch update
at com.xpn.xwiki.store.XWikiHibernateStore.saveXWikiDoc(XWikiHibernateStore.java:332)
at com.xpn.xwiki.store.XWikiCacheStore.saveXWikiDoc(XWikiCacheStore.java:97)
at com.xpn.xwiki.store.XWikiCacheStore.saveXWikiDoc(XWikiCacheStore.java:91)
at com.xpn.xwiki.XWiki.saveDocument(XWiki.java:1018)
at com.xpn.xwiki.web.SaveAction.save(SaveAction.java:120)
at com.xpn.xwiki.web.SaveAction.action(SaveAction.java:129)
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:147)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:117)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:541)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:619)

Wrapped Exception:

java.sql.BatchUpdateException: Duplicate entry '1801169637-BugTest.WebHome' for key 1
at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:1269)
at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:955)
at org.apache.commons.dbcp.DelegatingStatement.executeBatch(DelegatingStatement.java:294)
at org.apache.commons.dbcp.DelegatingStatement.executeBatch(DelegatingStatement.java:294)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:58)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:195)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:235)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:139)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:297)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:985)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:333)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
at com.xpn.xwiki.store.XWikiHibernateBaseStore.endTransaction(XWikiHibernateBaseStore.java:701)
at com.xpn.xwiki.store.XWikiHibernateBaseStore.endTransaction(XWikiHibernateBaseStore.java:675)
at com.xpn.xwiki.store.XWikiHibernateStore.saveXWikiDoc(XWikiHibernateStore.java:322)
at com.xpn.xwiki.store.XWikiCacheStore.saveXWikiDoc(XWikiCacheStore.java:97)
at com.xpn.xwiki.store.XWikiCacheStore.saveXWikiDoc(XWikiCacheStore.java:91)
at com.xpn.xwiki.XWiki.saveDocument(XWiki.java:1018)
at com.xpn.xwiki.web.SaveAction.save(SaveAction.java:120)
at com.xpn.xwiki.web.SaveAction.action(SaveAction.java:129)
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:147)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.xpn.xwiki.web.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:117)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:541)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at java.lang.Thread.run(Thread.java:619)