From c14852867786c798f98a23d075e76a2e2acce204 Mon Sep 17 00:00:00 2001
From: Christos Zoulas <christos@zoulas.com>
Date: Mon, 23 Aug 2021 08:30:57 -0400
Subject: [PATCH] - Expose HIST_PURGE - Compare pointer against null - Use
 initlex()

---
 sh.h     | 2 ++
 sh.lex.c | 6 ++----
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/sh.h b/sh.h
index 3c285a9e..77e801c6 100644
--- a/sh.h
+++ b/sh.h
@@ -78,6 +78,7 @@ typedef unsigned long intptr_t;
 #if defined(KANJI) && defined(WIDE_STRINGS) && defined(HAVE_NL_LANGINFO) && defined(CODESET)
 #define AUTOSET_KANJI
 #endif
+
 /*
  * Sanity
  */
@@ -1027,6 +1028,7 @@ EXTERN struct varent {
  * The following are for interfacing redo substitution in
  * aliases to the lexical routines.
  */
+#define HIST_PURGE	-500000
 EXTERN struct wordent *alhistp IZERO_STRUCT;/* Argument list (first) */
 EXTERN struct wordent *alhistt IZERO_STRUCT;/* Node after last in arg list */
 EXTERN Char  **alvec IZERO_STRUCT,
diff --git a/sh.lex.c b/sh.lex.c
index 5b0c6d8d..afe053e5 100644
--- a/sh.lex.c
+++ b/sh.lex.c
@@ -153,8 +153,7 @@ lex(struct wordent *hp)
 
     if (!postcmd_active)
 	btell(&lineloc);
-    hp->next = hp->prev = hp;
-    hp->word = STRNULL;
+    initlex(hp);
     hadhist = 0;
     do
 	c = readc(0);
@@ -711,7 +710,7 @@ getexcl(Char sc)
 
     lastev = eventno;
     hp = gethent(sc);
-    if (hp == 0)
+    if (hp == NULL)
 	return;
     hadhist = 1;
     dol = 0;
@@ -901,7 +900,6 @@ getsub(struct wordent *en)
  * We raise the limit to 50000000
  */
 
-#define HIST_PURGE -50000000
 static struct wordent *
 dosub(Char sc, struct wordent *en, int global)
 {