Fix closePath by using PDF command

[KurtGokhan]

For context2d.closePath, PDF command h can be used as seen in PDF spec

Fixes: #3293

[Uzlopak]

When I modified that code long time ago, I realized that it is not preferable to always close the path, e.g. on page breaks...
Should be careful while doing this

[KurtGokhan]

I will convert this to draft. This does not to solve the moveTo + arc fill problem. I will also investigate multiple pages.

[KurtGokhan]

Fixed the problem mentioned in the issue and added test.

Some HTML references were changed. Those were using rect call and manually closing the path. But now it is using closePath command. There are some subpixel differences, but the new method should be the correct one.

@Uzlopak what is the worst that could happen? Will it break the pdf? How should I test it? The old code was also closing path (using h) for arcs. But it was doing it in a wrong place.

[Uzlopak]

Hi Kurt,

I remember when I refactored context2d API command by API command and it had issues with the closePath. It had this bug because I could not figure out how to solve it properly.

Currently I am just the nagging old maintainer, who just gives hints for potential issues :). HackbrettXXX takes care of the project, so it is on him if there is a bug.

Worst what can happen is that the arcs are broken.

[KurtGokhan]

@HackbrettXXX any luck with this?

[Uzlopak]

@KurtGokhan your Branch is now out of date. Please rebase or merge latest master into your branch.

[HackbrettXXX]

I think it looks mostly good.

Could you add a test case where there is an implicit lineTo from the current position to the arc start? E.g.

ctx.beginPath()
ctx.moveTo(100,100)
ctx.arc(100,100,30,0,2)
ctx.fill()
ctx.stroke()

[KurtGokhan]

Done. Seemed strange at first but apparently that is how it is supposed to look.

Canvas:

PDF:

[HackbrettXXX]

Alright, looks good. Thanks for the PR!