From 04a68ad191cfcb87cdff70a6b913721e423cd28b Mon Sep 17 00:00:00 2001
From: Christos Zoulas <christos@zoulas.com>
Date: Mon, 23 Aug 2021 08:31:59 -0400
Subject: [PATCH] Fix bug reported by Jan Macku:     alias postcmd '/bin/echo
 -n "COMMAND:"'"'"'\!#:-$:gx'"'"''     echo 1 2 3 4 5     ^P prints     echo 1
 2 3 4 Reason: domod() enters junk history entries with event number
 HIST_PURGE aliasrun which is used to run postcmd modifies the history
 appending those entries. Fix by explicitly cleaning up those entries in
 aliasrun

---
 sh.decls.h |  1 +
 sh.hist.c  | 11 +++++++++++
 tc.func.c  |  2 ++
 3 files changed, 14 insertions(+)

diff --git a/sh.decls.h b/sh.decls.h
index e230becd..1ac9716e 100644
--- a/sh.decls.h
+++ b/sh.decls.h
@@ -217,6 +217,7 @@ extern  int	  	  t_pmatch	(const Char *, const Char *,
  */
 extern	void	 	  dohist	(Char **, struct command *);
 extern  struct Hist 	 *enthist	(int, struct wordent *, int, int, int);
+extern  void		  cleanhist	(void);
 extern	void	 	  savehist	(struct wordent *, int);
 extern	char		 *fmthist	(int, ptr_t);
 extern	void		  rechist	(Char *, int);
diff --git a/sh.hist.c b/sh.hist.c
index 14d862a3..40660bdc 100644
--- a/sh.hist.c
+++ b/sh.hist.c
@@ -1184,6 +1184,17 @@ dohist(Char **vp, struct command *c)
     }
 }
 
+void
+cleanhist(void)
+{
+    struct Hist *hp, *np;
+
+    for (hp = &Histlist; (np = hp->Hnext) != NULL;) {
+	if (np->Hnum != HIST_PURGE)
+	    return;
+	hremove(np), hfree(np);
+    }
+}
 
 char *
 fmthist(int fmt, ptr_t ptr)
diff --git a/tc.func.c b/tc.func.c
index 9f2b1a29..df4aa7a3 100644
--- a/tc.func.c
+++ b/tc.func.c
@@ -999,6 +999,7 @@ aliasrun(int cnt, Char *s1, Char *s2)
 
     getexit(osetexit);
     if (seterr) {
+	cleanhist();
 	xfree(seterr);
 	seterr = NULL;	/* don't repeatedly print err msg. */
     }
@@ -1075,6 +1076,7 @@ aliasrun(int cnt, Char *s1, Char *s2)
     }
     cleanup_until(&w);
     pendjob();
+    cleanhist();
     /* Restore status */
     setv(STRstatus, putn((tcsh_number_t)status), VAR_READWRITE);
 }