I just noticed this comment in scan.l:
* GUC variables. This is a DIRECT violation of the warning given at the
* head of gram.y, ie flex/bison code must not depend on any GUC variables;
* as such, changing their values can induce very unintuitive behavior.
* But we shall have to live with it as a short-term thing until the switch
* to SQL-standard string syntax is complete.
int backslash_quote = BACKSLASH_QUOTE_SAFE_ENCODING;
bool escape_string_warning = true;
bool standard_conforming_strings = true;
I'm not exactly sure what else needs to happen to remove these forbidden
GUCs and if we are not prepared to do this now when will we ever be...