Stroke overlap results in transparency

[selipso]

This is related to (or a byproduct of) #253 where two paths overlapping with each other results in their union becoming a transparent stroke, as shown below. Notice the monitor and the left ear of the alarm clock (the right ear is fine).

This is more noticeable with the image below, where the strokes' intersection is rendered the same color as their background, rather than being stacked on top of each other.

[GreLI]

Could you provide some sample images? (Github converts loaded images to PNG.)

[paperboyo]

Hello,

This - and things disappearing completely - is the single most dangerous thing about SVGO that makes it impossible to be used without human supervision, IMHO. Here is a graphic that exhibits the problem with default SVGO config (I am really sorry for the lengthy piece of code):

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     width="118.2px" height="90.3px" viewBox="0 0 118.2 90.3" enable-background="new 0 0 118.2 90.3" xml:space="preserve">
<g>
    <g>
        <g>
            <path fill="#EE4036" d="M61.1,37.5h-12c-2.1,0-4.1,0.6-5.8,1.6V67c1.7,1,3.7,1.6,5.8,1.6h12c2.1,0,4.1-0.6,5.8-1.6V43.7H71
                C69.2,40,65.4,37.5,61.1,37.5z"/>
            <path fill="#840B17" d="M66.4,22.9l-5-6.3c-1.5-1.9-3.9-3.1-6.3-3.1c-2.5,0-4.8,1.1-6.3,3.1l-5,6.3c-2.5,3.2-2.2,7.8,0.6,10.6
                l5,5c1.6,1.6,3.6,2.4,5.7,2.4c2.1,0,4.1-0.8,5.7-2.4l5-5C68.6,30.7,68.9,26.1,66.4,22.9z"/>
            <path fill="#231F20" d="M57.8,37.5"/>
            <rect x="43.3" y="52.8" fill="#1B75BB" width="23.6" height="15.9"/>
            <path fill="#D0AD97" d="M63.3,28c0-1-0.5-1.8-1.3-2.2c-0.5-3.4-3.4-6.1-6.9-6.1c-3.6,0-6.5,2.6-6.9,6.1c-0.8,0.4-1.3,1.3-1.3,2.2
                c0,0.9,0.5,1.8,1.3,2.2c0,3.9,3.1,7,7,7c3.9,0,7-3.1,7-7C62.8,29.8,63.3,29,63.3,28z"/>
            <path fill="#754C28" d="M62.8,25.5c-0.5,0.2-1.1,0.4-1.8,0.4c0.4,0.7,0.7,1.6,0.7,2.4c0.1,0,0.2,0,0.3,0c0.3,0,0.6,0,0.8,0.1
                v-2.6C62.8,25.6,62.8,25.5,62.8,25.5z"/>
            <path fill="#754C28" d="M47.4,25.5c0.5,0.2,1.1,0.4,1.8,0.4c-0.4,0.7-0.7,1.6-0.7,2.4c-0.1,0-0.2,0-0.3,0c-0.3,0-0.6,0-0.8,0.1
                v-2.6C47.3,25.6,47.3,25.5,47.4,25.5z"/>
            <path fill="#D0AD97" d="M63.3,28c0-1-0.5-1.8-1.3-2.2c-0.5-3.4-3.4-6.1-6.9-6.1c-3.6,0-6.5,2.6-6.9,6.1c-0.8,0.4-1.3,1.3-1.3,2.2
                c0,0.9,0.5,1.8,1.3,2.2c0,3.9,3.1,7,7,7c3.9,0,7-3.1,7-7C62.8,29.8,63.3,29,63.3,28z"/>
            <path fill="#836F61" d="M57.5,35c-0.6-0.7-1.4-1.1-2.4-1.1c-1,0-1.8,0.4-2.4,1.1H57.5z"/>
            <path fill="#754C28" d="M59.3,22.9c0,1.7,1.4,3.1,3.1,3.1c0.1,0,0.2,0,0.3,0c0-0.1,0-0.2,0-0.3c0-2.1-0.8-3.9-2.1-5.3
                C59.9,20.9,59.3,21.8,59.3,22.9z"/>
            <path fill="#754C28" d="M50.8,22.9c0,1.7-1.4,3.1-3.1,3.1c-0.1,0-0.2,0-0.3,0c0-0.1,0-0.2,0-0.3c0-2.1,0.8-3.9,2.1-5.3
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            <path fill="#754C28" d="M47.5,24.5c1.5,0.7,3.2,1.1,4.9,1.1c3.6,0,6.9-1.6,9.1-4.2c-1.4-2.1-3.7-3.5-6.4-3.5
                C51.2,18,48,20.8,47.5,24.5z"/>
            <path fill="#EE4036" d="M66.4,22.9l-5-6.3c-1.5-1.9-3.9-3.1-6.3-3.1c-2.5,0-4.8,1.1-6.3,3.1l-5,6.3c-2.5,3.2-2.2,7.8,0.6,10.6
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            <path fill="#840B17" d="M55.1,37.2c-2.1,0-4.1-1-5.4-2.5h-2.2l7.6,7.6l7.6-7.6h-2.2C59.1,36.2,57.2,37.2,55.1,37.2z"/>
            <path fill="#754C28" d="M49.6,21.3c1.7,0,3.3-0.4,4.7-1h0c0,2.6-2.1,4.7-4.7,4.7c-2.6,0-4.7-2.1-4.7-4.7h0
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            <path fill="#754C28" d="M52.9,19.8c1.7,0,2.6,3.7,0,3.7c-2.6,0-4.7-2.1-4.7-4.7h0C49.6,19.5,51.2,19.8,52.9,19.8z"/>
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                c0,1.2-0.9,2.2-2,2.2"/>
            <path fill="none" stroke="#840B17" stroke-width="2.0364" stroke-linecap="round" stroke-miterlimit="10" d="M56.6,44.1l0,9.5
                c0,1.2,0.9,2.2,2,2.2"/>
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            <rect x="46.6" y="55.2" fill="#EE4036" width="8.6" height="8.7"/>
            <path fill="#EE4036" d="M63.4,37.8v17.4h-8.3v8.7h8.6v-0.1c4.9-1.1,8.5-5.5,8.5-10.7v-4.6C72.1,43.2,68.4,38.8,63.4,37.8z"/>
            <path fill="#D0AD97" d="M55.1,63.9h1.8h4.7c0-3.8-2.8-7-6.5-7.6V63.9z"/>
        </g>
        <g>
            <path fill="#2E3191" d="M108.3,12.6l-5-6.3c-1.5-1.9-3.9-3.1-6.3-3.1c-2.5,0-4.8,1.1-6.3,3.1l-5,6.3c-2.5,3.2-2.2,7.8,0.6,10.6
                l5,5c1.6,1.6,3.6,2.4,5.7,2.4c2.1,0,4.1-0.8,5.7-2.4l5-5C110.5,20.3,110.8,15.8,108.3,12.6z"/>
            <path fill="#D0AD97" d="M103.5,16.4c0-3.9-3.1-7-7-7c-3.9,0-7,3.1-7,7c0,0.6,0,2.9,0,3.5c0,3.9,3.1,7,7,7c3.9,0,7-3.1,7-7
                C103.5,19.2,103.5,17,103.5,16.4z"/>
            <path fill="#754C28" d="M90.4,10.9c-1.7,0-3.3-0.4-4.7-1h0c0,2.6,2.1,4.7,4.7,4.7c2.6,0,4.7-2.1,4.7-4.7h0
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            <path fill="#754C28" d="M95.9,10.5c-1,0-1.9-0.3-2.5-0.8c-1.7,0-3.3-0.4-4.7-1h0c0,2.6,2.1,4.7,4.7,4.7c1.5,0,2.7-0.7,3.6-1.7
                c-0.2-0.4-0.4-0.8-0.5-1.3C96.3,10.5,96.1,10.5,95.9,10.5z"/>
            <path fill="#754C28" d="M95,12c1.3,0.2,2.5,0.1,3.7,0.3c1.6,0.3,3.1,1.1,4.5,2c-0.9-2.9-3.5-5-6.7-5c-2.1,0-4,0.9-5.2,2.4
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            <path fill="#754C28" d="M100,11c-1.1,0-2-0.4-2.7-0.9c-0.7,1-1.8,1.6-3.3,1.6c-0.3,0-0.6,0-0.9-0.1c-0.5,0.3-1.2,0.4-1.9,0.4
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            <path fill="#754C28" d="M102.5,12.9c0,1.7,0.4,3.3,1,4.7v0c-2.6,0-4.7-2.1-4.7-4.7c0-2.6,2.1-4.7,4.7-4.7v0
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                C104.3,15.1,105.4,16.3,105.4,17.7z"/>
            <path fill="#231F20" d="M99.2,27.2"/>
            <circle fill="#836F61" cx="95.3" cy="23.7" r="0.9"/>
            <path fill="#754C28" d="M94.5,9.6c-0.4,0-0.8,0.1-1.2,0.1c-1.7,0-3.3-0.4-4.7-1h0c0,0.7,0.2,1.4,0.5,2.1
                c-1.2-0.1-2.4-0.4-3.5-0.9h0c0,2.6,2.1,4.7,4.7,4.7c1.2,0,2.3-0.4,3.1-1.2c1.5,0,2.8-0.7,3.7-1.8c0,0,0,0-0.1-0.1
                C95.8,11.3,95,10.6,94.5,9.6z"/>
        </g>
    </g>
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</svg>

Thanks for looking into this!

Regards
Mateusz

[GreLI]

Issue with strokes was fixed in the recent commits, other than that it's a duplicat.

[GreLI]

v0.5.1 with the fix has been just published.