From 7d6f6a3532997fc2d9ad9d113e8c210e05971801 Mon Sep 17 00:00:00 2001
From: Jilles Tjoelker <jilles@FreeBSD.org>
Date: Sun, 15 Jul 2018 09:14:30 +0000
Subject: [PATCH] sh: Don't use padvance() for MAIL/MAILPATH

Using padvance() requires undoing its append of '/' and prevents adjusting
its '%' logic to allow most directories with '%' in PATH.

No functional change is intended.
---
 bin/sh/mail.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/bin/sh/mail.c b/bin/sh/mail.c
index 0a77bae7a808..194f654484db 100644
--- a/bin/sh/mail.c
+++ b/bin/sh/mail.c
@@ -43,7 +43,6 @@ __FBSDID("$FreeBSD$");
  */
 
 #include "shell.h"
-#include "exec.h"	/* defines padvance() */
 #include "mail.h"
 #include "var.h"
 #include "output.h"
@@ -72,9 +71,9 @@ void
 chkmail(int silent)
 {
 	int i;
-	const char *mpath;
+	char *mpath;
 	char *p;
-	char *q;
+	char *msg;
 	struct stackmark smark;
 	struct stat statb;
 
@@ -83,22 +82,25 @@ chkmail(int silent)
 	if (nmboxes == 0)
 		return;
 	setstackmark(&smark);
-	mpath = mpathset()? mpathval() : mailval();
+	mpath = stsavestr(mpathset()? mpathval() : mailval());
 	for (i = 0 ; i < nmboxes ; i++) {
-		p = padvance(&mpath, "");
-		if (p == NULL)
-			break;
+		p = mpath;
 		if (*p == '\0')
-			continue;
-		for (q = p ; *q ; q++);
-		if (q[-1] != '/')
-			abort();
-		q[-1] = '\0';			/* delete trailing '/' */
+			break;
+		mpath = strchrnul(mpath, ':');
+		if (*mpath != '\0') {
+			*mpath++ = '\0';
+			if (p == mpath - 1)
+				continue;
+		}
+		msg = strchr(p, '%');
+		if (msg != NULL)
+			*msg++ = '\0';
 #ifdef notdef /* this is what the System V shell claims to do (it lies) */
 		if (stat(p, &statb) < 0)
 			statb.st_mtime = 0;
 		if (statb.st_mtime > mailtime[i] && ! silent) {
-			out2str(pathopt? pathopt : "you have mail");
+			out2str(msg? msg : "you have mail");
 			out2c('\n');
 		}
 		mailtime[i] = statb.st_mtime;
@@ -106,7 +108,7 @@ chkmail(int silent)
 		if (stat(p, &statb) < 0)
 			statb.st_size = 0;
 		if (statb.st_size > mailtime[i] && ! silent) {
-			out2str(pathopt? pathopt : "you have mail");
+			out2str(msg? msg : "you have mail");
 			out2c('\n');
 		}
 		mailtime[i] = statb.st_size;