uuid_transfer causes crash

[eschmidbauer]

Describe the bug After a video call is bridged, we use uuid_transfer to transfer the A-leg of a call to an extension which triggers and echo application. This causes a crash. gdb backtrace indicates it's related to the b-leg session being NULL. Sometimes the issue does not occur, I suspect a race condition maybe happening where the transfer is executed too fast (e.g instantly after the bridge)

To Reproduce Steps to reproduce the behavior:

1. Bridge video call
2. execute uuid_transfer [channel id of a-leg] extension to echo

Expected behavior Expect b-leg hangup, echo video to display to a-leg

Package version or git hash

• FreeSWITCH Version 1.10.11-dev+git~20231107T155030Z~11048483d3~64bit (git 1104848 2023-11-07 15:50:30Z 64bit)

Trace logs https://pastebin.freeswitch.org/view/77382421

backtrace from core file https://pastebin.freeswitch.org/view/65917f2a