BePDF crashes on quit after adding an annotation

[grexe]

not sure if it's the same crash as #3 since there is no stacktrace attached to that issue, but since it's over 10 years old I thought I'd open a fresh one and linking to it.

This is reproducable:

1. open any PDF
2. add an annotation (e.g. highlighting)
3. quit BePDF

crash with a double free in GString(), see attachment.

Using Haiku R1/Develop hrev58787 and BePDF 2.1.4

BePDF-3816-debug-02-04-2025-15-30-03.report.txt

[humdingerb]

FWIW, I can't reproduce with 64bit Haiku Beta5. Simply adding a highlight annotation and quitting BePDF does not crash.

#3, however is still reproducible, when adding an annotation ans saving: crash after an alert claimed to have successfully saved the PDF.