Sync 'minimal' branch with 'master'.

.bash_logout

@@ -1,7 +1,7 @@
 #!/bin/bash - not strictly necessary, but helps nano with syntax highlighting.
 
 # Clear the screen/console on logout.
-if (( $SHLVL == 1 )); then
+if (( SHLVL == 1 )); then
   if [[ -x /usr/bin/clear_console ]]; then
     /usr/bin/clear_console -q
   elif [[ -x /usr/bin/clear ]]; then
@@ -9,6 +9,19 @@ if (( $SHLVL == 1 )); then
   elif [[ -x /usr/bin/tput ]]; then
     /usr/bin/tput clear
   else
-    echo -ne "\E[2J"
+    echo -ne "\e[2J"
   fi
 fi
+
+hash ssh-add ssh-agent >/dev/null 2>&1 && {
+  # Stop any started ssh-agent as long as the shell level is 1 and we're not on a tty.
+  (( SHLVL == 1 )) && [[ "$(tty)" == /dev/pts/* ]] && [[ -n "$SSH_AGENT_PID" ]] && {
+    ssh-agent -k
+    (( $? != 0 )) && printf "\\033[1;31;40m%s\\033[0;39m\\n" "Failed to stop ssh-agent." >&2
+    sleep 5
+    unset SSH_AGENT_PID SSH_AUTH_SOCK
+  }
+
+  # Update the ~/.ssh/agents file.
+  __read_ssh_agents && __write_ssh_agents
+}