From 9f5a68a00248e5608c353c138c39f32d797d99dc Mon Sep 17 00:00:00 2001
From: Jilles Tjoelker <jilles@FreeBSD.org>
Date: Sun, 12 Dec 2010 00:07:27 +0000
Subject: [PATCH] sh: Remove the herefd hack.

The herefd hack wrote out partial here documents while expanding them. It
seems unnecessary complication given that other expansions just allocate
memory. It causes bugs because the stack is also used for intermediate
results such as arithmetic expressions. Such places should disable herefd
for the duration but not all of them do, and I prefer removing the need for
disabling herefd to disabling it everywhere needed.

Here documents larger than 1024 bytes will use a bit more CPU time and
memory.

Additionally this allows a later change to expand here documents in the
current shell environment. (This is faster for small here documents but also
changes behaviour.)

Obtained from:	dash
---
 bin/sh/expand.c   | 8 --------
 bin/sh/memalloc.c | 6 ------
 bin/sh/memalloc.h | 1 -
 3 files changed, 15 deletions(-)

diff --git a/bin/sh/expand.c b/bin/sh/expand.c
index f9c7f1b480d4..1693a0b87fd4 100644
--- a/bin/sh/expand.c
+++ b/bin/sh/expand.c
@@ -132,7 +132,6 @@ collate_range_cmp(int c1, int c2)
 void
 expandhere(union node *arg, int fd)
 {
-	herefd = fd;
 	expandarg(arg, (struct arglist *)NULL, 0);
 	xwrite(fd, stackblock(), expdest - stackblock());
 }
@@ -469,7 +468,6 @@ expbackq(union node *cmd, int quoted, int flag)
 	char lastc;
 	int startloc = dest - stackblock();
 	char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
-	int saveherefd;
 	int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 	int nnl;
 
@@ -477,15 +475,12 @@ expbackq(union node *cmd, int quoted, int flag)
 	saveifs = ifsfirst;
 	savelastp = ifslastp;
 	saveargbackq = argbackq;
-	saveherefd = herefd;
-	herefd = -1;
 	p = grabstackstr(dest);
 	evalbackcmd(cmd, &in);
 	ungrabstackstr(p, dest);
 	ifsfirst = saveifs;
 	ifslastp = savelastp;
 	argbackq = saveargbackq;
-	herefd = saveherefd;
 
 	p = in.buf;
 	lastc = '\0';
@@ -544,16 +539,13 @@ subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 	char *loc = NULL;
 	char *q;
 	int c = 0;
-	int saveherefd = herefd;
 	struct nodelist *saveargbackq = argbackq;
 	int amount;
 
-	herefd = -1;
 	argstr(p, (subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
 	    subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX ?
 	    EXP_CASE : 0) | EXP_TILDE);
 	STACKSTRNUL(expdest);
-	herefd = saveherefd;
 	argbackq = saveargbackq;
 	startp = stackblock() + startloc;
 	if (str == NULL)
diff --git a/bin/sh/memalloc.c b/bin/sh/memalloc.c
index d00b4d9afc67..47b5b839b99d 100644
--- a/bin/sh/memalloc.c
+++ b/bin/sh/memalloc.c
@@ -128,7 +128,6 @@ static struct stackmark *markp;
 char *stacknxt;
 int stacknleft;
 int sstrnleft;
-int herefd = -1;
 
 
 static void
@@ -309,11 +308,6 @@ growstackstr(void)
 	int len;
 
 	len = stackblocksize();
-	if (herefd >= 0 && len >= 1024) {
-		xwrite(herefd, stackblock(), len);
-		sstrnleft = len;
-		return stackblock();
-	}
 	return growstrstackblock(len);
 }
 
diff --git a/bin/sh/memalloc.h b/bin/sh/memalloc.h
index 88848ddd63b7..da23a95d5987 100644
--- a/bin/sh/memalloc.h
+++ b/bin/sh/memalloc.h
@@ -46,7 +46,6 @@ struct stackmark {
 extern char *stacknxt;
 extern int stacknleft;
 extern int sstrnleft;
-extern int herefd;
 
 pointer ckmalloc(size_t);
 pointer ckrealloc(pointer, int);