- Prior to this update, the trap handler could, under certain circumstances, lose signals during another trap initialization. This update blocks the signal while the trap string and handler are being modified. Now, the signals are no longer lost.
- Prior to this update, the manual page for trap in Bash did not mention that signals ignored upon entry cannot be listed later. This is now fixed and the manual page entry text is amended to "Signals ignored upon entry to the shell cannot be trapped, reset or listed".
- Prior to this update, the Bash shell called the trap handler within a signal handler when a SIGCHLD signal was received in job control mode and a handler for the signal was installed. This was a security risk and could cause Bash to enter a deadlock or to terminate unexpectedly with a segmentation fault due to memory corruption. With this update, the trap handler is now called outside of the signal handler, and Bash no longer enters a deadlock.
- This update enables the system-wide "/etc/bash.bash_logout" file. This allows administrators to write system-wide logout actions for all users.
- When a trap handler was invoked while running another trap handler, which was invoked during a pipeline call, bash was unresponsive. With this update, pipeline calls are saved and subsequently restored in this scenario, and bash responds normally.