Update SVGBezierPath.mm

[markm68k]

• Ensure that pathBySettingSVGAttributes: always returns a non-null value. • If [self copy] returns nil, return self or create a new instance as a fallback. • Add a comment explaining the fallback.

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[markm68k]

Addresses open issue #229

[markm68k]

I'm not certain this is the right fix. However with the current implementation if copy fails, the method will return nil.

Perhaps this is the safest option, as callers can check for nil and handle errors appropriately, avoiding accidental unintended mutations if returning self.

If the decision is to allow returning nil, then changing the header file for pathBySettingSVGAttributes: should be defined as such in the header.

[arielelkin]

falling back to self when self copy returns nil breaks the contract of this method, because callers expect a distinct instance. how about:

Suggested change

	// Fallback if copy returns nil, ensure non-null return.
	path = self;
	// Fallback if copy returns nil, ensure non-null return.
	SVGBezierPath *newPath = [SVGBezierPath bezierPathWithCGPath:self.CGPath];
	newPath.lineWidth = self.lineWidth;
	newPath.flatness = self.flatness;
	newPath.miterLimit = self.miterLimit;
	path = newPath;

[markm68k]

Agreed. I like this fallback solution much better.