SVG animation / dirty path - animation

Question

Could anybody explain me how to remove a point in my path and why did it come from?
window.onload =function(){
var myHeart = $("#Heart");
var current = 0;
var PathTail_MainPath = $("#PathTail_MainPath");
var tailMainPath = $("#tailMainPath");
myHeart.click(function () {
if (current++ % 2 == 0) {
PathTail_MainPath.toggleClass("tailMainPath tailMainPathReturn");
tailMainPath.toggleClass("tailMainPath tailMainPathReturn");
console.log("one");
} else {
PathTail_MainPath.toggleClass("tailMainPath tailMainPathReturn");
tailMainPath.toggleClass("tailMainPath tailMainPathReturn");
console.log("two");
}
});
};
#Heart {
width: 600px;
border: 1px solid #000;
cursor: pointer;
}
#Heart .tailMainPath {
-webkit-animation: tailStroke 500ms linear;
animation: tailStroke 500ms linear;
-webkit-animation-fill-mode: forwards;
animation-fill-mode: forwards;
}
#Heart .tailMainPathReturn {
-webkit-animation: tailStrokeReturn 500ms linear 125ms;
animation: tailStrokeReturn 500ms linear 125ms;
-webkit-animation-fill-mode: forwards;
animation-fill-mode: forwards;
}
#-webkit-keyframes tailStroke {
0% {
stroke-dasharray: 0 150;
stroke-dashoffset: 0;
}
100% {
stroke-dasharray: 150 0;
stroke-dashoffset: 150;
}
}
#keyframes tailStroke {
0% {
stroke-dasharray: 0 150;
stroke-dashoffset: 0;
}
100% {
stroke-dasharray: 150 0;
stroke-dashoffset: 150;
}
}
#-webkit-keyframes tailStrokeReturn {
0% {
stroke-dasharray: 150 0;
stroke-dashoffset: 150;
}
100% {
stroke-dasharray: 0 150;
stroke-dashoffset: 0;
}
}
#keyframes tailStrokeReturn {
0% {
stroke-dasharray: 150 0;
stroke-dashoffset: 150;
}
100% {
stroke-dasharray: 0 150;
stroke-dashoffset: 0;
}
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<svg version="1.1" id="Heart" class="moving" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
viewBox="0 0 450 320" style="enable-background:new 0 0 450 320;" xml:space="preserve">
<defs>
<path id="PathTail_MainPath" class="tailMainPathReturn" d="M296.2,253.9l9.1-3.8l8,0.2c2.5,0.5,8.3,1.6,10.9,6.5c3.9,7.5,0.6,18.3-4.3,24.9
c-0.8,1.1-7.5,10.2-19.4,9.5c-9-0.5-13.8-4.1-18.6-8.1c-5.2-4.3-7.6-9.6-12.4-16.9c-3.7-5.7-6.9-13.5-16-22.4"/>
<path id="tailMainPath" class="tailMainPathReturn" d="M296.2,253.9l9.1-3.8l8,0.2c2.5,0.5,8.3,1.6,10.9,6.5c3.9,7.5,0.6,18.3-4.3,24.9
c-0.8,1.1-7.5,10.2-19.4,9.5c-9-0.5-13.8-4.1-18.6-8.1c-5.2-4.3-7.6-9.6-12.4-16.9c-3.7-5.7-6.9-13.5-16-22.4"/>
</defs>
<use xlink:href="#PathTail_MainPath" fill="none"; stroke="#000" stroke-width="11"/>
<use xlink:href="#tailMainPath" fill="none"; stroke="#A50808" stroke-linecap="round" stroke-width="9"/>
</svg>
PS This code doesn't work on code generator stackoverflow's.(I don't know why) That why I made copy here https://jsfiddle.net/BlackStar1991/ea6255h1/

Answer 1

The dirty dot is caused by "0 length" sub path with rounded line cap. When value of stroke-dashoffset is 0, the path is split by [0, 150]. So it has "0 length" sub path.
To solve this problem, you can offset the start point of line dash a bit.
#keyframes tailStroke {
0% {
stroke-dasharray: 0 151;
stroke-dashoffset: 1;
}
100% {
stroke-dasharray: 151 0;
stroke-dashoffset: 151;
}
}
#keyframes tailStrokeReturn {
0% {
stroke-dasharray: 151 0;
stroke-dashoffset: 151;
}
100% {
stroke-dasharray: 0 151;
stroke-dashoffset: 1;
}
}