Loading SVG fails for some files

[villares]

Most appropriate sub-area of Processing 4?

IO ?

Processing version

4.4.7

Operating system

Windows/macOS/Linux

Bug description

Unable to load some SVG files, such as https://commons.wikimedia.org/wiki/File:Aiga_departingflights.svg you get something similar to:

ArrayIndexOutOfBoundsException: Index 43 out of bounds for length 43

Steps to reproduce this

1. Launch PDE, create a sketch, download https://commons.wikimedia.org/wiki/File:Aiga_departingflights.svg and add it to the data folder of your sketch.

2. Run the snippet below:

void setup(){
  size(500, 500);
  PShape svg = loadShape("Aiga_departingflights.svg");
  shape(svg);  // will crash before this line... 
}

Additional context

This looks a bit like #750 but the "SVG path notation parsing issue" that causes it to fail seems different.

The provided failing SVG looks like this:

<svg xmlns="http://www.w3.org/2000/svg" version="1.0" viewBox="0 0 29 29">
<path d="m0 6 3-2 15 4 7-7a2 2 0 013 3l-7 7 4 15-2 3-7-13-5 5v4l-2 2-2-5-5-2 2-2h4l5-5z"/>
</svg>

If you scale it a bit on Inkscape you get a different path notation and it works fine:

<svg xmlns="http://www.w3.org/2000/svg" version="1.0" viewBox="0 0 29 29">
<path d="m 0,5.9994379 2.9997,-1.9998 14.9985,3.9996 6.9993,-6.99930004 a 2.1211082,2.1211082 0 0 1 2.9997,2.99970004 l -6.9993,6.9993001 3.9996,14.9985 -1.9998,2.9997 -6.9993,-12.9987 -4.9995,4.9995 v 3.9996 l -1.9998,1.9998 -1.9998,-4.9995 -4.9995,-1.9998 1.9998,-1.9998 h 3.9996 l 4.9995,-4.9995 z"/>
</svg>

Would you like to work on the issue?

No, I’m just reporting the issue

[hxrshxz]

hey @catilac I would like to work on this can you assign it to me

[catilac]

Hi @hxrshxz yeah that sounds good! Happy to assign it to you. Could you share what your approach will be for this?

[hxrshxz]

hey @catilac Thanks for assigning this to me! My plan is to first replicate the ArrayIndexOutOfBoundsException. From there, I will debug the loadShape function, focusing specifically on the SVG path parsing logic to pinpoint the exact line of code and data causing the issue. Once I've identified the root cause which I think is a loop boundary or notation handling error I will implment a fix. after I am done I willl verify the solution not only with the original failing SVG but also with other standard SVGs just to be sure. Let me know if this approach sounds good

[catilac]

sounds good! i'll check out your PR when it's ready :)