NullPointerException in HibernateDocumentDAO.findTags() when firstLetter is null

[Blucecio]

A NullPointerException was detected in the application log while processing requests to the TagsData servlet.

The exception occurs in HibernateDocumentDAO.findTags() at line 672, where String.toLowerCase() is invoked on a null firstLetter parameter.

Error details:
`text
java.lang.NullPointerException:
Cannot invoke "String.toLowerCase()"
because "firstLetter" is null

at com.logicaldoc.core.document.HibernateDocumentDAO.findTags(HibernateDocumentDAO.java:672)
at com.logicaldoc.web.data.TagsDataServlet.buildTagsMap(TagsDataServlet.java:130)
at com.logicaldoc.web.data.TagsDataServlet.service(TagsDataServlet.java:51)
`

The exception was logged twice within approximately one second.

Observed behavior:

No visible malfunction was noticed while using LogicalDOC. The application appears to operate normally, and the issue was discovered only by inspecting the server logs.

Expected behavior:

The tag retrieval process should handle a null firstLetter parameter gracefully, without throwing an exception.

Suggested investigation:

Verify whether HibernateDocumentDAO.findTags() properly handles null values for the firstLetter parameter and whether TagsDataServlet can invoke this method without providing a valid value.

The complete stack trace is attached.

[Blucecio]

Error stacktrace from main log file dms.log

[admin]

the log does not seem from a 9.3.1, the empty or null first letter is properly handled in the 9.3.1 and the line 672 is empty in the code of 9.3.1.

For me at least since 9.3.1 the problem is no more there