minor edits and prep for use in calc v2

Author: lcn2

README.md

@@ -289,7 +289,7 @@ help environment
 ```
 
 contains information regarding how environment variables can be
-used to configure some aspects of calc.  In calc v3, if `CALCRC`,
+used to configure some aspects of calc.  If `CALCRC`,
 `CALCPATH`, and `CALCHISTFILE` are unset, calc first checks the
 relevant XDG base directory environment variables and uses them when
 they name usable absolute directories.

help/environment

@@ -12,7 +12,7 @@ Environment variables
         $XDG_DATA_HOME and $XDG_CONFIG_HOME.  When both
         name usable absolute directories, calc uses:
 
-                    .:./cal:$XDG_DATA_HOME/calc:$XDG_CONFIG_HOME/calc:${CALC_SHAREDIR}:${CUSTOMCALDIR}
+                    .:./cal:${XDG_DATA_HOME}/calc:${XDG_CONFIG_HOME}/calc:${CALC_SHAREDIR}:${CUSTOMCALDIR}
 
         Otherwise a compiled value is used, which is usually:
 
@@ -34,7 +34,7 @@ Environment variables
         $XDG_CONFIG_HOME.  When it names a usable absolute
         directory, calc uses:
 
-                    ./.calcinit:$XDG_CONFIG_HOME/calc/calcrc:${CALC_SHAREDIR}/startup
+                    ./.calcinit:${XDG_CONFIG_HOME}/calc/calcrc:${CALC_SHAREDIR}/startup
 
         Otherwise a compiled value is used, which is usually:
 
@@ -101,7 +101,7 @@ Environment variables
 
         If this variable does not exist, or if this
         variable is an empty string, calc first checks
-        $XDG_STATE_HOME and uses $XDG_STATE_HOME/calc/history
+        $XDG_STATE_HOME and uses ${XDG_STATE_HOME}/calc/history
         when that names a usable absolute directory.
         Otherwise ~/.calc_history is used.
 
@@ -135,7 +135,7 @@ you'll need to run:
 in order to have the history mechanism if you choose a path to a file
 that doesn't exist.
 
-## Copyright (C) 1999,2021  Landon Curt Noll
+## Copyright (C) 1999,2021,2026  Landon Curt Noll
 ##
 ## Calc is open software; you can redistribute it and/or modify it under
 ## the terms of the version 2.1 of the GNU Lesser General Public License

hist.c

@@ -132,6 +132,7 @@ static void lowercase_word(int key);
 static void ignore_char(int key);
 static void arrow_key(int key);
 static void quit_calc(int key) __attribute__((noreturn));
+static void hist_mkdir_parent(void);
 
 static FUNC funcs[] = {{"ignore-char", ignore_char},
                        {"flush-input", flush_input},