Added keepRepeatCommandNames option to .toString() method

[danburzo]

With this PR I've added the ability to drop the optimization regarding repeat command names in the string output.

I also wanted to start a discussion on whether this is the right approach here. As per the SVG 1.2 spec (SVG 2 is similar):

If a 'moveto' is followed by multiple pairs of coordinates, the subsequent pairs shall be treated as implicit 'lineto' commands.

So it's not correct to automatically transform M 10 10 M 10 100 M 100 100 M 100 10 Z to M 10 10 10 100 100 100 100 10 Z, as seen in this example (notice the difference in rendering): http://jsfiddle.net/u0eym6d7/

While it would be better to treat all the specific cases where removing repeat command names does not result in equivalent paths, this is a quick fix to disable that optimization.

Edit: I fixed it through the extra parameter so that existing behavior is not changed. I've checked the SVG spec and the M seems to be the only command affected by this, so the alternative can be changing the condition to:
skipCmd = i > 0 && (this.segments[i][0] === this.segments[i - 1][0] && this.segments[i][0].toLowerCase() !== 'm');

Waiting for your thoughts on this :-)

[puzrin]

Thanks for clear example.

Is this fix for bug workaround only or you need unclamped notation for something else? If workaround only, i could try to write a direct fix (not clamp multiple M to one).

[danburzo]

At the moment it's only to work around the bug, and on second thought a direct fix would work better I think. 👍 I was reluctant to alter existing behavior, and assumed there might be other use cases for disabling the clamping.

[emiltamas]

Also related: svg/svgo#189

[danburzo]

I've closed the PR since the more I think about it the more this is the wrong approach :-)
We can move the relevant discussion to an issue I guess.

[puzrin]

@danburzo this param looks very specific. I could understand, if it disabled all opts, not single one. My suggestion is:

• fix M&m clamping directly
• add param to disable all opts OR postpone that until more problem happens

@emiltamas thanks for ref.

[puzrin]

Try 2.1.1, should fix that bug.

Thanks for your help!

[danburzo]

Looks good, thank you!