agent: reject edit calls whose new= text contains [upto]#421
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aledesogusbusiness-hue wants to merge 1 commit into
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agent: reject edit calls whose new= text contains [upto]#421aledesogusbusiness-hue wants to merge 1 commit into
aledesogusbusiness-hue wants to merge 1 commit into
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[upto] is an anchor marker that belongs only in the old= parameter of an edit tool call. If the model accidentally emits it in the new= parameter the literal string gets spliced into the file, leaving obvious corruption that triggers the system to retry the same patch, which fails again with the same outcome. Guard agent_tool_edit() against this: return a Tool error immediately when new_text contains "[upto]" so the model gets corrective feedback instead of writing the marker to disk. Fixes: antirez#408 Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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Problem
[upto]is an anchor marker that belongs only in theold=parameter of anedittool call, where it acts as a range wildcard between a unique head and tail.If the model accidentally emits
[upto]inside thenew=parameter,agent_tool_edit()passesnew_textstraight toagent_apply_file_splice(), which splices the literal string — including[upto]— into the file. The resulting file corruption triggers the system to retry the patch, which fails again with the same outcome, looping.Fix
Add a guard in
agent_tool_edit()that returns aTool errorimmediately whennew_textcontains"[upto]". This gives the model corrective feedback on the next turn rather than writing the marker to disk.Test plan
new=includes[upto]; verify the tool returns the error string and leaves the file unchanged.[upto]only inold=are unaffected.Fixes #408
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