From: Christian Kastner <ckk@kvr.at>
Date: Tue, 22 Dec 2015 15:55:38 +0100
Subject: crontab: warn about missing newline

Make crontab(1) refuse to add/replace a crontab with a missing newline before
EOF. The daemon will either not execute the last entry, or refuse to execute
the entire crontab (depending on the implementation).

Bug-Debian: https://bugs.debian.org/79037
Forwarded: no
Last-Update: 2015-12-22
Index: cron/crontab.c
===================================================================
--- cron.orig/crontab.c
+++ cron/crontab.c
@@ -509,6 +509,7 @@ replace_cmd() {
 	char	n[MAX_FNAME], envstr[MAX_ENVSTR], tn[MAX_FNAME];
 	FILE	*tmp;
 	int	ch, eof;
+	int	nl = FALSE;
 	entry	*e;
 	time_t	now = time(NULL);
 	char	**envp = env_init();
@@ -560,6 +561,8 @@ replace_cmd() {
 		switch (load_env(envstr, tmp)) {
 		case ERR:
 			eof = TRUE;
+			if (envstr[0] == '\0')
+				nl = TRUE;
 			break;
 		case FALSE:
 			e = load_entry(tmp, check_error, pw, envp);
@@ -576,6 +579,13 @@ replace_cmd() {
 		fclose(tmp);  unlink(tn);
 		return (-1);
 	}
+
+	if (nl == FALSE) {
+		fprintf(stderr, "new crontab file is missing newline before "
+				"EOF, can't install.\n");
+		fclose(tmp);  unlink(tn);
+		return (-1);
+	}
 
 #ifdef HAS_FCHOWN
 	if (fchown(fileno(tmp), ROOT_UID, -1) < OK)