RadToDeg: honour the absolute flag it already accepts

[redbluevn]

RadToDeg takes an absolute parameter and never reads it, so every conversion is normalised:

public static double RadToDeg(double value, bool absolute = true)
{
    var result = value * RadToDegFactor;
    return NormalizeAngle(result);   // absolute is unused
}

This is the CSUtilities half of what you described on DomCR/ACadSharp#1237 — "the issue then is in CSUtilities, it should allow the option for non absolute values". The ACadSharp side is @mediummandoo's PR; this only makes the flag work, and changes nothing for any existing caller, all of which use the default.

Why it matters. Normalising each endpoint on its own destroys a full sweep. -π and π both become 180, so a 360° span is written as the same number twice, and a reader that only calls DegToRad cannot get it back.

ACadSharp writes hatch boundary arc and ellipse angles through this method, and a circular boundary is stored exactly that way. Measured over a set of real drawings: 25 such boundaries across 4 of them, out of 13,371 arc and 338 ellipse boundary edges. A DXF round trip of one drawing returned three arcs with a zero sweep.

What AutoCAD 2027 says, on a minted 43 KB drawing holding one hatch bounded by a circle of radius 40 about (100, 100):

written with	AUDIT	EXTMIN..EXTMAX
the normalising conversion	opened, 0 errors	(60, 100)..(60, 100) — a single point
absolute: false	opened, 0 errors	(60, 60)..(140, 140) — the circle

Note the audit column: AutoCAD does not consider the first file damaged. It simply has no fill where the circle was. That is why this can go unnoticed.

The π..3π shape also occurs in those drawings and writes 180 and 540, outside the -360..360 range you mentioned, so it was put to AutoCAD as well: opened, 0 errors, extents are the whole circle.

Tests: three cases on the ACadSharp side pin the round trip for both edge types and the flag itself, and all three are red with either half reverted. On this repository the suite is unchanged, since no existing caller passes false.

🤖 Generated with Claude Code