Department of State Authorization Act of 2019 This bill authorizes, revises, and repeals various provisions related to the Department of State. The bill provides statutory authority to establish an Assistant Secretary for International Narcotics and Law Enforcement Affairs and an Assistant Secretary for Energy Diplomacy and Security and eliminates the position for the Special Representative and Policy Coordinator for Burma (Myanmar). The bill imposes limitations on special appointments not expressly authorized by Congress. The State Department may not implement any reduction-in-force actions unless it has provided justification to Congress. The State Department shall establish and implement a standard parental leave policy applicable to employees across all bureaus and offices. The State Department may waive various requirements related to hiring (1) certain employees with significant scientific, technological, or engineering expertise; or (2) Global Engagement Center employees. The State Department shall make certain efforts to promote diversity in its workforce, including expanding anti-harassment and antidiscrimination training and gathering data to devise ways to promote participation from a range of demographic categories in professional development programs. The State Department shall (1) semiannually consult with other departments and agencies regarding the security of certain information systems and commission independent penetration testing of such systems, (2) establish a process for security researchers to test State Department systems and submit information about discovered vulnerabilities, and (3) create a bug bounty program that provides rewards for information about previously unidentified security flaws in State Department information systems. The bill directs the State Department to take various actions to update its public diplomacy efforts, including establishing a Director of Research and Evaluation to assess existing programs. The State Department shall assess each country's capacity to combat public corruption. For countries that do not meet the minimum standards, the State Department shall utilize proper measures to combat corruption. The State Department shall establish a working group on security assistance, including activities such as peacekeeping and military financing assistance. The bill revises various requirements and limits related to such assistance and transferring defense articles to foreign countries. The State Department may designate an existing official to coordinate all U.S. government matters relating to the long-term disposition of Islamic State of Iraq and Syria (ISIS) detainees.