Patch-Source: https://src.fedoraproject.org/rpms/at/blob/f36/f/at-3.2.2-shell.patch
--
From d72ffaead4a4410fe7b91570d290baac991a69eb Mon Sep 17 00:00:00 2001
From: Jan Staněk <jstanek@redhat.com>
Date: Mar 31 2022 10:13:56 +0000
Subject: shell: add preceding newline to delimiter

at uses heredoc redirection to pass the script being executed
into user's defined $SHELL. However, the heredoc delimiter
is directly concatenated to the script's contents;
if these contents do not end with a newline,
the delimiter is attached to the last line of the script.

This patch adds a single newline to be always emmited before the
delimiter. This guarantees the delimiter is always on it's own
line. In case a newline is already present at the end of the original
script, this simply adds a single empty line; I cannot think of any
complication that could result from that.

Resolves: rhbz#2070450

diff -ur b/at.c a/at.c
--- b/at.c
+++ a/at.c
@@ -62,11 +62,8 @@
 #include <stdlib.h>
 #include <string.h>

-#ifdef TM_IN_SYS_TIME
 #include <sys/time.h>
-#else
 #include <time.h>
-#endif

 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
@@ -245,6 +242,12 @@
     int kill_errno;
     int rc;
     int mailsize = 128;
+    struct timeval tv;
+    struct timezone tz;
+    long int i;
+
+    gettimeofday(&tv, &tz);
+    srandom(getpid()+tv.tv_usec);

 /* Install the signal handler for SIGINT; terminate after removing the
  * spool file if necessary
@@ -492,6 +495,9 @@
     fprintf(fp, " || {\n\t echo 'Execution directory "
 	    "inaccessible' >&2\n\t exit 1\n}\n");

+    i = random();
+    fprintf(fp, "${SHELL:-/bin/sh} << \'marcinDELIMITER%08lx\'\n", i);
+
     istty = isatty(fileno(stdin));
     if (istty) {
 	runtime = localtime(&runtimer);
@@ -512,7 +518,7 @@
     if (istty) {
 	fprintf(stderr, "<EOT>\n");
     }
-    fprintf(fp, "\n");
+    fprintf(fp, "\nmarcinDELIMITER%08lx\n", i);
     if (ferror(fp))
 	panic("Output error");
     fflush(fp);