[SVG] Interval should not be created if a value in begin-value-list doesn't have a matching value i…

LayoutTests/svg/animations/script-tests/animate-no-matching-end-value.js

+description("Test animate intervals having begin-value without a matching end-value");
+embedSVGTestCase("resources/animate-no-matching-end-value.svg");
+
+// Setup animation test
+function sample1() {
+    shouldBeCloseEnough("rect1.x.animVal.value", "0");
+    shouldBe("rect1.x.baseVal.value", "0");
+}
+
+function sample2() {
+    shouldBeCloseEnough("rect1.x.animVal.value", "100");
+    shouldBe("rect1.x.baseVal.value", "0");
+}
+
+function executeTest() {
+    var rects = rootSVGElement.ownerDocument.getElementsByTagName("rect");
+    rect1 = rects[0];
+
+    const expectedValues = [
+        // [animationId, time, sampleCallback]
+        ["anim", 0.0,   sample1],
+        ["anim", 1.0,   sample2],
+        ["anim", 2.0,   sample1],
+        ["anim", 3.0,   sample2],
+        ["anim", 4.0,   sample1],
+        ["anim", 5.0,   sample1]
+    ];
+
+    runAnimationTest(expectedValues);
+}
+
+window.animationStartsImmediately = true;
+var successfullyParsed = true;