From 1d9093e6032136db90de0ee0ba53ed68282e79e6 Mon Sep 17 00:00:00 2001
From: Johnothan King <johnothanking@protonmail.com>
Date: Sun, 25 Apr 2021 16:12:29 -0700
Subject: [PATCH] Add support for process substitutions to the deparser (#288)

Like tdump() and trestore() before commit 32d1abb1, sh_deparse() fails
to handle process substitutions correctly. This limitation of the shell
deparser is rather minor since it's unused. However, seeing as the
deparser was left in the code base intentionally it should at least
function properly.

src/cmd/ksh93/sh/deparse.c:
- Add a PROCSUBST flag for handling process substitutions in
  sh_deparse().
- If we're handling a process substitution, add an ending ')'
  without an extra newline.
- Avoid adding an extra ' &' to commands inside of a process
  substitution. An extra ' &' is only added if the FAMP and FINT
  flags are set, which indicates the command was spawned as a separate
  job with '&'.
- Add process substitution handling to 'p_redirect' by calling p_tree()
  when encountering a process substitution.
---
 src/cmd/ksh93/sh/deparse.c | 38 +++++++++++++++++++++++++-------------
 1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/src/cmd/ksh93/sh/deparse.c b/src/cmd/ksh93/sh/deparse.c
index e37e7e5c9..4a922cb19 100644
--- a/src/cmd/ksh93/sh/deparse.c
+++ b/src/cmd/ksh93/sh/deparse.c
@@ -40,9 +40,10 @@
 
 
 /* flags that can be specified with p_tree() */
-#define NO_NEWLINE	1
-#define NEED_BRACE	2
-#define NO_BRACKET	4
+#define NO_NEWLINE	(1 << 0)
+#define NEED_BRACE	(1 << 1)
+#define NO_BRACKET	(1 << 2)
+#define PROCSUBST	(1 << 3)
 
 static void p_comlist(const struct dolnod*,int);
 static void p_arg(const struct argnod*, int endchar, int opts);
@@ -62,8 +63,6 @@ static const struct ionod *here_doc;
 static Sfio_t *outfile;
 static const char *forinit = "";
 
-extern void sh_deparse(Sfio_t*, const Shnode_t*,int);
-
 void sh_deparse(Sfio_t *out, const Shnode_t *t,int tflags)
 {
 	outfile = out;
@@ -77,9 +76,12 @@ static void p_tree(register const Shnode_t *t,register int tflags)
 	register char *cp;
 	int save = end_line;
 	int needbrace = (tflags&NEED_BRACE);
+	int procsub = (tflags&PROCSUBST);
 	tflags &= ~NEED_BRACE;
 	if(tflags&NO_NEWLINE)
 		end_line = ' ';
+	else if(procsub)
+		end_line = ')';
 	else
 		end_line = '\n';
 	switch(t->tre.tretyp&COMMSK)
@@ -113,7 +115,7 @@ static void p_tree(register const Shnode_t *t,register int tflags)
 		case TFORK:
 			if(needbrace)
 				tflags |= NEED_BRACE;
-			if(t->tre.tretyp&(FAMP|FCOOP))
+			if((t->tre.tretyp&(FAMP|FCOOP)) && (t->tre.tretyp&(FAMP|FINT))!=FAMP)
 			{
 				tflags = NEED_BRACE|NO_NEWLINE;
 				end_line = ' ';
@@ -125,12 +127,12 @@ static void p_tree(register const Shnode_t *t,register int tflags)
 				p_redirect(t->fork.forkio);
 			if(t->tre.tretyp&FCOOP)
 			{
-				sfputr(outfile,"|&",'\n');
+				sfputr(outfile,"|&",procsub?')':'\n');
 				begin_line = 1;
 			}
-			else if(t->tre.tretyp&FAMP)
+			else if((t->tre.tretyp&(FAMP|FINT))==(FAMP|FINT))
 			{
-				sfputr(outfile,"&",'\n');
+				sfputr(outfile,"&",procsub?')':'\n');
 				begin_line = 1;
 			}
 			break;
@@ -401,13 +403,13 @@ static void p_arg(register const struct argnod *arg,register int endchar,int opt
 		else if(opts)
 			flag = ' ';
 		cp = arg->argval;
-		if(*cp==0 && (arg->argflag&ARG_EXP)  && arg->argchn.ap)
+		if(*cp==0 && (arg->argflag&ARG_EXP) && arg->argchn.ap)
 		{
+			/* process substitution */
 			int c = (arg->argflag&ARG_RAW)?'>':'<';
 			sfputc(outfile,c);
 			sfputc(outfile,'(');
-			p_tree((Shnode_t*)arg->argchn.ap,0);
-			sfputc(outfile,')');
+			p_tree((Shnode_t*)arg->argchn.ap,PROCSUBST);
 		}
 		else if(*cp==0 && opts==POST && arg->argchn.ap)
 		{
@@ -489,7 +491,17 @@ static void p_redirect(register const struct ionod *iop)
 		}
 		if((iof&IOLSEEK) && (iof&IOARITH))
 			iof2 = iof, iof = ' ';
-		if(iop->iodelim)
+		if((iop->iofile & IOPROCSUB) && !(iop->iofile & IOLSEEK))
+		{
+			/* process substitution as argument to redirection */
+			if(iop->iofile & IOPUT)
+				sfwrite(outfile,">(",2);
+			else
+				sfwrite(outfile,"<(",2);
+			p_tree((Shnode_t*)iop->ioname,PROCSUBST);
+			sfputc(outfile,iof);
+		}
+		else if(iop->iodelim)
 		{
 			if(!(iop->iofile&IODOC))
 				sfwrite(outfile,"''",2);