pidgin/pidgin

Fix an out of bounds write in purple_markup_linkify.
release-2.x.y
2021-07-08, Gary Kramlich
71df0a528a5a
Fix an out of bounds write in purple_markup_linkify.

This was found by Thomas Roth , Dominik Maier
, and Fabian Freyer .

Testing Done:
Compiled and ran the `purple_markup_linkify_fuzzer` from the google oss-fuzz project to verify the fix.

Reviewed at https://reviews.imfreedom.org/r/781/
For information on writing a plugin for Purple, Pidgin or Finch, go
http://developer.pidgin.im and click on API. From there, see the
HOWTOs in the "Related Pages" section.
You can also generate this documentation locally by installing
doxygen and graphviz dot, then running "make docs" in the
source tree. The documentation will be in the docs/html directory.