Painless Safety: Regexes #49873
Description
The painless regex engine can have unbounded memory and/or CPU usage, leading to a cumbersome user settings to turn on/off. If regexes were safer, we could be safe when they are on and thus remove the setting.
We'll achieve this by setting a max number of characters to consider.
The setting can initially be global, but we can make it per context or even as a compiler setting/option. For the latter, we need to develop an api for passing the options.
Related: #30139