Worked on the vim/vim repository to address a bug affecting PowerShell command execution within Vim’s system() function. Focused on improving cross-shell compatibility, the developer implemented a solution in C and Vim script that correctly wraps compound PowerShell commands using & { ... }, preventing E282 errors and enabling reliable multi-command execution when pwsh or powershell is set as the shell. This patch, included upstream as commit 20b2365c5f382a4c61cd6b082c37019e789d7cd4, enhanced scripting reliability for PowerShell users and streamlined automation workflows. The work demonstrated careful debugging and a strong understanding of shell scripting and Vim internals.