Fix off-by-one indexing bug in DouglasPeucker simplify#387
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asinghvi17 wants to merge 1 commit intomainfrom
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Fix off-by-one indexing bug in DouglasPeucker simplify#387asinghvi17 wants to merge 1 commit intomainfrom
asinghvi17 wants to merge 1 commit intomainfrom
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The while loop condition allowed `i` to reach `max_points` before incrementing, causing a BoundsError when accessing `results[i]` after `i += 1`. This occurred when simplifying small geometries with low `number` or `ratio` values. Fixes #386 Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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Feb 2, 2026
| start_idx, end_idx = 1, npoints | ||
| max_idx, max_dist = _find_max_squared_dist(points, start_idx, end_idx) | ||
| while i ≤ min(MIN_POINTS + 1, max_points) || (i < max_points && max_dist > max_tol) | ||
| while i < min(MIN_POINTS + 1, max_points) || (i < max_points && max_dist > max_tol) |
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This is a fix, but I'm not sure what it means in terms of the algorithm (should MIN_POINTS + 1 become MIN_POINTS?). There's also preserve_endpoint that extends the length with 1 when true, does that matter here?
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Summary
numberorratiovaluesProblem
In the DouglasPeucker
_simplifyfunction, the while loop condition:allowed
ito equalmax_pointsand enter the loop. Theni += 1would makei = max_points + 1, causingresults[i]to be out of bounds since the array is sized for exactlymax_pointselements.Fix
Changed
i ≤toi <in the first part of the condition:Test plan
Fixes #386
🤖 Generated with Claude Code