Hi,
I noticed that after
commit 8255c7a5eeba8f1a38b7a431c04909bde4f5e67d
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date:   2019-05-22 13:04:48 -0400
    Phase 2 pgindent run for v12.
    
    Switch to 2.1 version of pg_bsd_indent.  This formats
    multiline function declarations "correctly", that is with
    additional lines of parameter declarations indented to match
    where the first line's left parenthesis is.
    
    Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
a few prototypes look odd. It appears to be cases where previously the
odd indentation was put to some use, by indenting parameters less:
extern void DefineCustomBoolVariable(
                         const char *name,
                         const char *short_desc,
                         const char *long_desc,
                         bool *valueAddr,
                         bool bootValue,
                         GucContext context,
                         int flags,
                         GucBoolCheckHook check_hook,
                         GucBoolAssignHook assign_hook,
                         GucShowHook show_hook);
but now that looks odd:
extern void DefineCustomBoolVariable(
                                     const char *name,
                                     const char *short_desc,
                                     const char *long_desc,
                                     bool *valueAddr,
                                     bool bootValue,
                                     GucContext context,
                                     int flags,
                                     GucBoolCheckHook check_hook,
                                     GucBoolAssignHook assign_hook,
                                     GucShowHook show_hook);
Unless somebody protests I'm going to remove the now pretty useless
looking newline in the cases I can find. I used
ack --type cc --type cpp '^[a-zA-Z_].*\(\n'
to find the ones I did. Not sure that catches everything.
Greetings,
Andres Freund