fix issue with read builtin delimiter in invaild mutibyte char; fix crash if caller passes negative count argument to one of the history file writing functions

tests/complete.right

@@ -172,9 +172,10 @@ privileged
 verbose
 vi
 xtrace
-autocd
 array_expand_once
 assoc_expand_once
+autocd
+bash_source_fullpath
 cdable_vars
 cdspell
 checkhash

tests/shopt.right

@@ -1,9 +1,10 @@
 ./shopt.tests: line 15: shopt: -z: invalid option
 shopt: usage: shopt [-pqsu] [-o] [optname ...]
 --
-shopt -u autocd
 shopt -u array_expand_once
 shopt -u assoc_expand_once
+shopt -u autocd
+shopt -u bash_source_fullpath
 shopt -u cdable_vars
 shopt -s cdspell
 shopt -u checkhash
@@ -79,9 +80,10 @@ shopt -s progcomp
 shopt -s promptvars
 shopt -s sourcepath
 --
-shopt -u autocd
 shopt -u array_expand_once
 shopt -u assoc_expand_once
+shopt -u autocd
+shopt -u bash_source_fullpath
 shopt -u cdable_vars
 shopt -u checkhash
 shopt -u checkjobs
@@ -124,9 +126,10 @@ shopt -u shift_verbose
 shopt -u varredir_close
 shopt -u xpg_echo
 --
-autocd         	off
 array_expand_once	off
 assoc_expand_once	off
+autocd         	off
+bash_source_fullpath	off
 cdable_vars    	off
 checkhash      	off
 checkjobs      	off
@@ -307,5 +310,9 @@ xtrace         	off
 --
 ./shopt.tests: line 106: shopt: xyz1: invalid shell option name
 ./shopt.tests: line 107: shopt: xyz1: invalid option name
+4c4
+< bash_source_fullpath	on
+---
+> bash_source_fullpath	off
 expand_aliases 	on
 expand_aliases 	on