setjmp/longjmp are used to jump out of signal handlers. That
causes weirdness. Use sigsetjmp/siglongjmp.

--- a/main.c
+++ b/main.c
@@ -20,7 +20,7 @@
 
 extern		trapint(); /* defined below */
 extern char	*getenv();
-jmp_buf		jmpenv;
+sigjmp_buf	jmpenv;
 
 #ifndef NO_DIGRAPH
 static init_digraphs();
@@ -310,7 +310,7 @@ int main(argc, argv)
 	 */
 	while (mode != MODE_QUIT)
 	{
-		if (setjmp(jmpenv))
+		if (sigsetjmp(jmpenv, 1))
 		{
 			/* Maybe we just aborted a change? */
 			abortdo();
@@ -371,7 +371,7 @@ int trapint(signo)
 #else
 	signal(signo, trapint);
 #endif
-	longjmp(jmpenv, 1);
+	siglongjmp(jmpenv, 1);
 
 	return 0;
 }
--- a/tio.c
+++ b/tio.c
@@ -350,10 +350,10 @@ static struct _keymap
 
 #if !MSDOS && !TOS
 # if BSD || COHERENT
-static jmp_buf env_timeout;
+static sigjmp_buf env_timeout;
 static int dummy()
 {
-	longjmp(env_timeout, 1);
+	siglongjmp(env_timeout, 1);
 	return 0;
 }
 # else 
@@ -552,7 +552,7 @@ int getkey(when)
 	while (j > 1)
 	{
 #if BSD || COHERENT
-		if (setjmp(env_timeout))
+		if (sigsetjmp(env_timeout, 1))
 		{
 			/* we timed out - assume no mapping */
 			j = 0;