xdebug fallsbacks too often

[apolopena]

Describe the bug

The xdebug log show this when it first starts up and debug_on or debug_off is called:

[5382] [Config] INFO: Trigger value for 'XDEBUG_TRIGGER' not found, falling back to 'XDEBUG_SESSION'
[5382] [Config] INFO: Trigger value for 'XDEBUG_SESSION' not found, so not activating
[5382] [Config] INFO: Trigger value for 'XDEBUG_TRIGGER' not found, falling back to 'XDEBUG_SESSION'
[5382] [Config] INFO: Trigger value for 'XDEBUG_SESSION' not found, so not activating
[5382] [Config] INFO: Trigger value for 'XDEBUG_TRIGGER' not found, falling back to 'XDEBUG_SESSION'
[5382] [Config] INFO: Trigger value for 'XDEBUG_SESSION' not found, so not activating

Screenshots

Steps to reproduce

Expected behavior

Additional information

[apolopena]

This is expected behavior. xdebug falls back to XDEBUG_SESSION when using XDEBUG_SESSION_START in a GET request which is the mechanism we use to toggle xdebug sessions on and off. The alternative would be to use XDEBUG_SESSION in a get request instead of XDEBUG_SESSION_START but is unecessary due to the fallback mechanism that xdebug uses.

[apolopena]

Reopening since the xdebug fallback mechanism makes multiple calls and fallback on every trigger of a debug session and everytime something is debugged. This is an optimization.

[apolopena]

This optimization requires a full refactoring of the debug_on and debug_off browser funtions as well as all xdebug configs.