Unclear What the internal check tests and what the new splitting rule matches are not known.
What
To decide whether a command is safe or matches a permission rule, Claude Code first picks out the command's name, its first word. In the PowerShell safe-command check, PowerShell being the Windows command shell, and in a second place that reads command names, Claude Code now uses a different rule for splitting on spaces and trimming the start of the command when an internal check is true. Before, it split on any whitespace.
Why
The command name decides which permission rules apply, so a change here can change which commands are allowed without asking.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
What the internal check tests and what the new splitting rule matches are not known.