code: plan9front

Download patch

ref: 2839760066e578e449ebc8b3d71297b9f79a8c99
parent: 217e8a06198cf6681fb0c38c26f34d96ae4302f6
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Sat Sep 8 10:49:00 EDT 2018

rc: fix Xpipefd unbalancing the redir stack

Xpipefd wants the pipe descriptor to be closed in turfredir(), so
it pushes the redirection, but this breaks Xpopredir after normal
redirection. so we shuffle the Xpipefd redir to the bottom of the
stack.

--- a/sys/src/cmd/rc/exec.c
+++ b/sys/src/cmd/rc/exec.c
@@ -123,6 +123,21 @@
 	runq->redir = rp;
 }
 
+void
+shuffleredir(void)
+{
+	redir **rr, *rp;
+
+	rp = runq->redir;
+	if(rp==0)
+		return;
+	runq->redir = rp->next;
+	rp->next = runq->startredir;
+	for(rr = &runq->redir; *rr != rp->next; rr = &((*rr)->next))
+		;
+	*rr = rp;
+}
+
 var*
 newvar(char *name, var *next)
 {
--- a/sys/src/cmd/rc/fns.h
+++ b/sys/src/cmd/rc/fns.h
@@ -55,6 +55,7 @@
 word*	searchpath(char*);
 void	setstatus(char*);
 void	setvar(char*, word*);
+void	shuffleredir(void);
 void	skipnl(void);
 void	start(code*, int, var*);
 int	truestatus(void);
--- a/sys/src/cmd/rc/havefork.c
+++ b/sys/src/cmd/rc/havefork.c
@@ -185,7 +185,8 @@
 	default:
 		addwaitpid(pid);
 		close(sidefd);
-		pushredir(ROPEN, mainfd, mainfd);	/* isn't this a noop? */
+		pushredir(ROPEN, mainfd, mainfd);
+		shuffleredir();	/* shuffle redir to bottom of stack for turfredir() */
 		strcpy(name, Fdprefix);
 		inttoascii(name+strlen(name), mainfd);
 		pushword(name);