Spritezero produces invalid content boxes

[dwoznicki]

Running spritezero on certain SVGs with a content box that is close to the edge of the bounding box sometimes produces a content box that extends beyond the bounds of the sprite.

For example, when I create a spritesheet from the SVG below using the JS snippet in the README, I get the following output.

SVG content

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg
   xmlns:dc="http://purl.org/dc/elements/1.1/"
   xmlns:cc="http://creativecommons.org/ns#"
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns="http://www.w3.org/2000/svg"
   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
   version="1.0"
   width="22.999981"
   height="21.999981"
   id="svg2"
   inkscape:version="1.0.2 (e86c870879, 2021-01-15)"
   sodipodi:docname="US:AR_airport.svg">
  <metadata
     id="metadata3037">
    <rdf:RDF>
      <cc:Work
         rdf:about="">
        <dc:format>image/svg+xml</dc:format>
        <dc:type
           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
        <dc:title />
      </cc:Work>
    </rdf:RDF>
  </metadata>
  <sodipodi:namedview
     pagecolor="#ffffff"
     bordercolor="#666666"
     borderopacity="1"
     objecttolerance="10"
     gridtolerance="10"
     guidetolerance="10"
     inkscape:pageopacity="0"
     inkscape:pageshadow="2"
     inkscape:window-width="1920"
     inkscape:window-height="1029"
     id="namedview3035"
     showgrid="true"
     inkscape:showpageshadow="false"
     inkscape:zoom="14.151908"
     inkscape:cx="-7.4924318"
     inkscape:cy="10.999965"
     inkscape:window-x="0"
     inkscape:window-y="27"
     inkscape:window-maximized="1"
     inkscape:current-layer="svg2"
     inkscape:document-rotation="0"
     inkscape:pagecheckerboard="true">
    <inkscape:grid
       type="xygrid"
       id="grid3031"
       empspacing="5"
       visible="true"
       enabled="true"
       snapvisiblegridlinesonly="true"
       originx="-12.499994"
       originy="-13.000035" />
  </sodipodi:namedview>
  <defs
     id="defs4" />
  <path
     inkscape:connector-curvature="0"
     style="fill:#004187;fill-opacity:1;stroke-width:1"
     id="path3797"
     d="M 3.170379,20.381928 V 18.763903 H 2.039678 0.908976 V 12.771441 6.778978 L 0.46953,3.487356 C 0.227834,1.676964 0.023314,0.151695 0.01504,0.09787 L 0,0 h 10.316001 10.316001 l 0.132632,0.06205 c 0.211466,0.09893 0.307906,0.224501 0.371011,0.48308 0.04693,0.192348 0.05,0.239856 0.02525,0.391458 -0.0155,0.0949 -0.04299,0.284108 -0.06108,0.420466 -0.02605,0.196308 -0.05819,0.304973 -0.154386,0.521944 -0.115465,0.260418 -0.121922,0.286976 -0.130211,0.534993 l -0.0087,0.180973 0.09966,0.151766 0.09966,0.07177 h 0.99477 0.994772 v 0.633453 0.633453 l 0.0046,0.04333 C 22.9369,4.298897 22.9246,4.369277 22.9246,4.560288 l -0.159999,0.468231 -0.263645,0.662227 c -0.305261,0.659351 -0.345703,0.762625 -0.362218,0.924908 -0.02524,0.248071 -0.206229,1.066901 -0.301512,1.364086 -0.04266,0.133049 -0.121249,0.413603 -0.17465,0.623455 -0.100758,0.395931 -0.08756,0.448111 -0.382065,0.88535 -0.07039,0.104496 -0.223658,0.334819 -0.224226,0.453295 -1.59e-4,0.03428 -0.06614,0.271363 -0.244371,0.624627 -0.178744,0.354279 -0.339216,0.706658 -0.35786,0.78583 -0.03962,0.168251 -0.672368,1.328598 -1.15271,2.113875 -0.27362,0.447323 -0.34863,0.596896 -0.61995,1.236202 -0.193903,0.45689 -0.322573,0.796494 -0.346071,0.913402 -0.02058,0.102352 -0.05441,0.262431 -0.07521,0.35573 -0.02864,0.12856 -0.03793,0.341984 -0.03831,0.881499 l -5e-4,0.631865 0.08676,0.34678 c 0.04772,0.146728 0.110672,0.365772 0.139883,0.486763 0.02921,0.120992 0.06983,0.333548 0.09025,0.374571 0.03157,0.0634 0.03602,0.1817 0.02972,1.241173 l -0.0074,1.166582 -0.08354,0.250895 c -0.04594,0.094 -0.133578,0.2303 -0.194735,0.302908 -0.06115,0.07261 -0.111191,0.139763 -0.111191,0.149239 0,0.02417 -0.06754,0.09168 -0.09243,0.09238 -0.01135,3.2e-4 -0.04891,0.02354 -0.08345,0.05161 -0.06201,0.05038 -0.157371,0.05104 -7.443784,0.05161 l -7.380968,6e-4 v -1.618028 z" />
  <g
     aria-label="AIRPORT"
     transform="matrix(0.46883974,0,0,0.53323125,-2e-6,5e-6)"
     id="text3056"
     style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:11.2522px;line-height:0%;font-family:'Roadgeek 2005 Series D';-inkscape-font-specification:'Roadgeek 2005 Series D';text-align:center;letter-spacing:0px;word-spacing:0px;writing-mode:lr-tb;text-anchor:middle;fill:#ffffff;fill-opacity:1;stroke:none;stroke-width:1.87536"
     fill="#ffffff">
    <path
       d="M 6.4899225,2.2818776 5.2354105,5.6837111 H 7.7490129 Z M 5.9679722,1.3707539 h 1.048479 L 9.6216238,8.2064705 H 8.6601366 L 8.0374591,6.4529009 H 4.9561214 L 4.3334439,8.2064705 H 3.3582211 Z"
       style="font-size:9.37679px;line-height:1.25;stroke-width:1.87536"
       id="path18" />
    <path
       d="m 10.619739,1.3707539 h 0.924859 v 6.8357166 h -0.924859 z"
       style="font-size:9.37679px;line-height:1.25;stroke-width:1.87536"
       id="path20" />
    <path
       d="m 16.626746,5.001513 q 0.297603,0.1007272 0.576892,0.43038 0.283868,0.3296527 0.567735,0.9065451 l 0.938595,1.8680324 H 17.716431 L 16.841936,6.4529009 Q 16.503126,5.7661243 16.18263,5.5417772 15.866713,5.3174302 15.317292,5.3174302 H 14.310019 V 8.2064705 H 13.38516 V 1.3707539 h 2.087801 q 1.172099,0 1.748991,0.4899007 0.576892,0.4899006 0.576892,1.4788589 0,0.6455701 -0.302181,1.0713716 Q 17.19906,4.8366866 16.626746,5.001513 Z M 14.310019,2.1307867 v 2.4266107 h 1.162942 q 0.668463,0 1.007272,-0.3067602 0.343389,-0.3113387 0.343389,-0.9111237 0,-0.5997849 -0.343389,-0.9019666 -0.338809,-0.3067602 -1.007272,-0.3067602 z"
       style="font-size:9.37679px;line-height:1.25;stroke-width:1.87536"
       id="path22" />
    <path
       d="m 20.82524,2.1307867 v 2.5685445 h 1.162942 q 0.64557,0 0.998115,-0.3342312 0.352545,-0.3342313 0.352545,-0.9523303 0,-0.6135204 -0.352545,-0.9477517 Q 22.633752,2.1307867 21.988182,2.1307867 Z M 19.900381,1.3707539 h 2.087801 q 1.149206,0 1.735255,0.5219502 0.590628,0.5173718 0.590628,1.5200656 0,1.0118509 -0.590628,1.5292226 Q 23.137388,5.459364 21.988182,5.459364 H 20.82524 v 2.7471065 h -0.924859 z"
       style="font-size:9.37679px;line-height:1.25;stroke-width:1.87536"
       id="path24" />
    <path
       d="m 28.329419,1.9980099 q -1.007272,0 -1.602479,0.7508758 -0.590628,0.7508757 -0.590628,2.0465943 0,1.29114 0.590628,2.0420158 0.595207,0.7508757 1.602479,0.7508757 1.007273,0 1.593322,-0.7508757 0.590628,-0.7508758 0.590628,-2.0420158 0,-1.2957186 -0.590628,-2.0465943 -0.586049,-0.7508758 -1.593322,-0.7508758 z m 0,-0.7508758 q 1.437653,0 2.298413,0.9660658 0.86076,0.9614873 0.86076,2.5822801 0,1.6162143 -0.86076,2.58228 -0.86076,0.9614873 -2.298413,0.9614873 -1.442231,0 -2.307569,-0.9614873 -0.86076,-0.9614872 -0.86076,-2.58228 0,-1.6207928 0.86076,-2.5822801 0.865338,-0.9660658 2.307569,-0.9660658 z"
       style="font-size:9.37679px;line-height:1.25;stroke-width:1.87536"
       id="path26" />
    <path
       d="m 36.176987,5.001513 q 0.297603,0.1007272 0.576893,0.43038 0.283867,0.3296527 0.567735,0.9065451 L 38.26021,8.2064705 H 37.266673 L 36.392177,6.4529009 Q 36.053367,5.7661243 35.732872,5.5417772 35.416954,5.3174302 34.867533,5.3174302 H 33.860261 V 8.2064705 H 32.935402 V 1.3707539 h 2.0878 q 1.172099,0 1.748992,0.4899007 0.576892,0.4899006 0.576892,1.4788589 0,0.6455701 -0.302182,1.0713716 -0.297603,0.4258015 -0.869917,0.5906279 z M 33.860261,2.1307867 v 2.4266107 h 1.162941 q 0.668463,0 1.007273,-0.3067602 0.343388,-0.3113387 0.343388,-0.9111237 0,-0.5997849 -0.343388,-0.9019666 -0.33881,-0.3067602 -1.007273,-0.3067602 z"
       style="font-size:9.37679px;line-height:1.25;stroke-width:1.87536"
       id="path28" />
    <path
       d="m 37.820673,1.3707539 h 5.782659 V 2.1491007 H 41.176721 V 8.2064705 H 40.247284 V 2.1491007 h -2.426611 z"
       style="font-size:9.37679px;line-height:1.25;stroke-width:1.87536"
       id="path30" />
  </g>
  <g
     id="g3958"
     transform="matrix(0.03940848,0,0,0.03940848,-0.554787,-1.2295342)"
     style="stroke-width:2">
    <path
       inkscape:connector-curvature="0"
       style="fill:#ffffff;fill-opacity:1;fill-rule:evenodd;stroke:none;stroke-width:2"
       id="path3150"
       d="m 407.29132,160.93534 c -13.00139,4.27824 -26.00276,5.51325 -39.00414,12.91783 -8.36419,8.47139 -19.52985,36.55302 -29.38668,55.47294 -22.35389,2.31197 -31.16092,3.11915 -135.71303,65.18503 l 3.74011,-13.3576 h -11.75465 l -9.61745,11.22039 -55.03326,-30.98961 -24.57792,14.9605 11.22034,5.34305 33.12683,44.88147 -41.67566,42.74424 24.04362,-2.67151 30.9896,-34.19541 c 57.68925,4.15052 69.30799,-2.54677 106.86064,-9.61746 l -94.03736,83.88561 51.29311,-7.48025 72.13094,-69.45943 c 64.23036,-30.94631 42.37959,-16.22002 66.78789,-43.27857 25.11227,-12.07787 74.61221,-24.33723 75.33678,-46.48434 -5.05924,-10.43557 -23.50345,-7.48617 -35.26401,-11.2204 l 13.3245,-14.92745 -20.36502,-9.17768 -13.79733,2.19869 z" />
    <path
       inkscape:connector-curvature="0"
       style="fill:#004187;fill-opacity:1;fill-rule:evenodd;stroke:none;stroke-width:2"
       id="path3152"
       d="m 247.80867,291.29156 7.334,12.69076 20.02948,-9.92373 -8.01454,-12.77725 z" />
    <path
       inkscape:connector-curvature="0"
       style="fill:#004187;fill-opacity:1;fill-rule:evenodd;stroke:none;stroke-width:2"
       id="path3154"
       d="m 277.64707,292.63418 -8.00076,-12.76823 19.27618,-10.45331 9.32968,13.09732 z" />
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       inkscape:connector-curvature="0"
       style="fill:#004187;fill-opacity:1;fill-rule:evenodd;stroke:none;stroke-width:2"
       id="path3156"
       d="m 291.29249,268.37154 19.59148,-10.98759 10.89132,13.35757 -21.16693,10.39829 z" />
    <path
       inkscape:connector-curvature="0"
       style="fill:#004187;fill-opacity:1;fill-rule:evenodd;stroke:none;stroke-width:2"
       id="path3158"
       d="m 323.07664,243.46452 -6.93217,-2.20599 -3.15081,3.4248 -0.31531,11.6045 11.68588,13.04226 c 10.854,-7.23779 17.68197,-11.95331 25.22232,-18.09753 z" />
    <path
       inkscape:connector-curvature="0"
       style="fill:#004187;fill-opacity:1;fill-rule:evenodd;stroke:none;stroke-width:2"
       id="path3160"
       d="m 319.88338,234.90192 -2.04089,4.80873 33.55221,8.32988 1.65796,-10.68608 z" />
  </g>
  <rect
     id="mapbox-content"
     width="13.5"
     height="6.5"
     x="3.9999983"
     y="14.999977"
     fill="none"
     style="stroke-width:1" />
</svg>

{"US:AR_airport":{"width":22,"height":21,"x":0,"y":0,"pixelRatio":1,"content":[4,15,17.5,21.5]}}

While the height is 21px, the bottom right corner of the content box is set at 21.5px. This box is invalid, and causes my tileserver to choke when trying to load the spritesheet.