When multiple Appnames are set through newrelic_set_appname() only the first one receives exception stack traces through newrelic_notice_error()

[heldchen]

Description

in our setup we have an application that is contained of multiple parts, f.e. a backend, a frontend, an api site etc.. to not only have per-site metrics we configured the app names to include two identifierts, one for the entire project and one specific to the corresponding part in newrelic_set_appname. example: newrelic_set_appname('project;frontend');.

while all the application names are successfully receiving metrics, errors and exceptions that way, unfortunately only the first of the list of app names is also receiving stack traces of exceptions.

Steps to Reproduce

1. setup the latest newrelic php agent in the default way
2. in the php code at the start of the execution, run newrelic_set_appname('first;second');
3. in any piece of the code, send an Exception/Throwable object newrelic_notice_error($ex);
4. observe that while both apps will get the error reported, only the app first will have the full stack trace of the exception attached to the error

Expected Behavior

all applications where an error is reported to should contain the stack trace.

Relevant Logs / Console output

Your Environment

Description:	Debian GNU/Linux 10 (buster)
Release:	10
Codename:	buster

newrelic-php5:
  Installed: 10.0.0.312
  Candidate: 10.0.0.312
newrelic-php5-common:
  Installed: 10.0.0.312
  Candidate: 10.0.0.312
newrelic-daemon:
  Installed: 10.0.0.312
  Candidate: 10.0.0.312