From 4e5f24e38ce9d0fcb965122c0f58f079a2016cb9 Mon Sep 17 00:00:00 2001
From: Martijn Dekker <martijn@inlv.org>
Date: Wed, 22 Jul 2020 11:46:54 +0100
Subject: [PATCH] sh/xec.c: remove inactive and broken SHOPT_AMP code

This code has always been completely undocumented since it was
added sometime between 2002 and 2004[*]. No one (including Google)
knows what it's for and no one is likely to find out.

Not only that, it doesn't compile. If SHOPT_AMP is defined, then it
errors out on an undefined function `print_fun` and an undefined
member `shpath` of 'struct Shell_s'. So it's clear that the code
had been abandoned by its authors for some time as of 2012.

src/cmd/ksh93/sh/xec.c:
- Remove vestigial SHOPT_AMP stuff, whatever that was.

[*] Found out by searching multishell ksh93 repo:
    https://github.com/multishell/ksh93/
---
 src/cmd/ksh93/sh/xec.c | 19 +++----------------
 1 file changed, 3 insertions(+), 16 deletions(-)

diff --git a/src/cmd/ksh93/sh/xec.c b/src/cmd/ksh93/sh/xec.c
index 4f99919bf..f13c70d7c 100644
--- a/src/cmd/ksh93/sh/xec.c
+++ b/src/cmd/ksh93/sh/xec.c
@@ -941,7 +941,7 @@ int sh_exec(register const Shnode_t *t, int flags)
 		int 		execflg = (type&sh_state(SH_NOFORK));
 		int 		execflg2 = (type&sh_state(SH_FORKED));
 		int 		mainloop = (type&sh_state(SH_INTERACTIVE));
-#if SHOPT_AMP || SHOPT_SPAWN
+#if SHOPT_SPAWN
 		int		ntflag = (type&sh_state(SH_NTFORK));
 #else
 		int		ntflag = 0;
@@ -1573,18 +1573,6 @@ int sh_exec(register const Shnode_t *t, int flags)
 					pipes[2] = 0;
 					coproc_init(shp,pipes);
 				}
-#if SHOPT_AMP
-				if((type&(FAMP|FINT)) == (FAMP|FINT))
-					parent = sh_ntfork(shp,t,com,&jobid,ntflag);
-				else
-					parent = sh_fork(shp,type,&jobid);
-				if(parent<0)
-				{
-					if(shp->comsub==1 && usepipe && unpipe)
-						iounpipe(shp);
-					break;
-				}
-#else
 #if SHOPT_SPAWN
 #   ifdef _lib_fork
 				if(com)
@@ -1604,7 +1592,6 @@ int sh_exec(register const Shnode_t *t, int flags)
 #else
 				parent = sh_fork(shp,type,&jobid);
 #endif /* SHOPT_SPAWN */
-#endif
 			}
 			if(job.parent=parent)
 			/* This is the parent branch of fork
@@ -3380,7 +3367,7 @@ static void coproc_init(Shell_t *shp, int pipes[])
 #if SHOPT_SPAWN
 
 
-#if SHOPT_AMP || !defined(_lib_fork)
+#if !defined(_lib_fork)
 
 /*
  * create a shell script consisting of t->fork.forktre and execute it
@@ -3490,7 +3477,7 @@ static pid_t sh_ntfork(Shell_t *shp,const Shnode_t *t,char *argv[],int *jobid,in
 		otype = savetype;
 		savetype=0;
 	}
-#   if SHOPT_AMP || !defined(_lib_fork)
+#   if !defined(_lib_fork)
 	if(!argv)
 	{
 		register Shnode_t *tchild = t->fork.forktre;