[hakarrr]

Problem

With numeric spanGaps, adding a segment-style callback reconnects line sections that exceed the configured gap limit. For example, points at x=0,5,30,35 with spanGaps: 10 produce sections 0-1 and 2-3 without styling, but sections 0-1 and 1-3 with a segment.borderColor callback. The 25-unit gap is drawn despite the existing stop flag.

Change

Only reuse the previous style section's start when spanGaps === true. Numeric gap limits already produce separate solid sections, so start each styled section at its own boundary.

This preserves boolean gap-spanning behavior and does not change public APIs. It is independent of #12365, which addresses curve control points rather than style splitting.

Tests

• 28 added cases covering x/y index axes, reversed scales, uniform/changing colors, transparent canvas pixels inside forbidden gaps, repeated updates, boolean spans, numeric limits with no break, and skipped-point controls.
• Pristine master: 14 of the 28 cases fail. With the fix: all 28 pass.
• Fresh frozen-lockfile dependency install, then native Karma/ChromeHeadless suite: 1731/1731 pass.
• pnpm build including declaration generation and tsc --noEmit: pass.
• Changed-file ESLint: no errors, two existing complexity/statement-count warnings in _boundSegment.
• Actual before/after canvas rendering checked: the forbidden connecting line disappears while both intended sections remain.

Firefox and downstream integration suites were not run.