From: Robert Luberda <robert@debian.org>
Date: Tue, 7 Aug 2018 22:42:45 +0200
Subject: Fix compilation issues

Fix the following gcc issues:
- disable code that references to ALTWERASE that is not
  defined on Debian;
- use 'char' rather than 'unsigned char' to get rid of warnings
  about unsigned/signed conversions;
- check result of snprintf calls to fix `output might be
  truncated' warnings.
---
 fio.c   |  4 ++--
 popen.c |  6 +++++-
 tty.c   | 10 ++++++----
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/fio.c b/fio.c
index 26e34b6..35bcdd1 100644
--- a/fio.c
+++ b/fio.c
@@ -456,8 +456,8 @@ expand(char *name)
 			name = "~/mbox";
 		/* fall through */
 	}
-	if (name[0] == '+' && getfold(cmdbuf, sizeof(cmdbuf)) >= 0) {
-		(void)snprintf(xname, sizeof(xname), "%s/%s", cmdbuf, name + 1);
+	if (name[0] == '+' && getfold(cmdbuf, sizeof(cmdbuf)) >= 0 &&
+		snprintf(xname, sizeof(xname), "%s/%s", cmdbuf, name + 1) < sizeof(xname)) {
 		name = savestr(xname);
 	}
 	/* catch the most common shell meta character */
diff --git a/popen.c b/popen.c
index 92b14b0..5ed33cf 100644
--- a/popen.c
+++ b/popen.c
@@ -481,7 +481,11 @@ handle_spool_locks(int action)
 	int retval;
 	char lockpath[PATHSIZE];
 
-	snprintf(lockpath, PATHSIZE - 1, "%s.lock", mailname);
+	if (snprintf(lockpath, PATHSIZE - 1, "%s.lock", mailname) >= PATHSIZE)
+  {
+			warnx("Cannot create lock file for %s: %s", mailname, "Path too long");
+      return(1);
+  }
 	lockpath[PATHSIZE - 1] = '\0';
 
 	if (action == 0) {
diff --git a/tty.c b/tty.c
index ab10bdb..67d8a0f 100644
--- a/tty.c
+++ b/tty.c
@@ -104,8 +104,10 @@ grabh(struct header *hp, int gflags)
 		return(-1);
 	}
 	tty.keys = oldtio.c_cc;
+#ifdef ALTWERASE
 	if (oldtio.c_lflag & ALTWERASE)
 		tty.flags |= TTY_ALTWERASE;
+#endif
 
 	newtio = oldtio;
 	newtio.c_lflag &= ~(ECHO | ICANON);
@@ -175,7 +177,7 @@ char *
 readtty(char *pr, char *src)
 {
 	struct sigaction act, saveint;
-	unsigned char canonb[BUFSIZ];
+	char canonb[BUFSIZ];
 	char *cp;
 	sigset_t oset;
 	int c, done;
@@ -327,7 +329,7 @@ static int
 tty_getc(struct tty *t)
 {
 	ssize_t		n;
-	unsigned char	c;
+	char	c;
 
 	n = read(t->fdin, &c, 1);
 	switch (n) {
@@ -344,7 +346,7 @@ tty_getc(struct tty *t)
 static int
 tty_insert(struct tty *t, int c, int nocntrl)
 {
-	const unsigned char	*ws = " \t";
+	const char	*ws = " \t";
 
 	if (CCEQ(t->keys[VERASE], c)) {
 		if (nocntrl)
@@ -380,7 +382,7 @@ tty_insert(struct tty *t, int c, int nocntrl)
 static void
 tty_putc(struct tty *t, int c)
 {
-	unsigned char	cc = c;
+	char	cc = c;
 
 	write(t->fdout, &cc, 1);
 }