Don't iterate past the end of the metrics list

Source/core/layout/svg/SVGTextLayoutEngine.cpp

Index: Source/core/layout/svg/SVGTextLayoutEngine.cpp
diff --git a/Source/core/layout/svg/SVGTextLayoutEngine.cpp b/Source/core/layout/svg/SVGTextLayoutEngine.cpp
index 36d860b289ff2f66a0434c57e9e114383caacbb1..79956449be86a1beeb6dde89c195033f827e847d 100644
--- a/Source/core/layout/svg/SVGTextLayoutEngine.cpp
+++ b/Source/core/layout/svg/SVGTextLayoutEngine.cpp
@@ -357,7 +357,7 @@ void SVGTextLayoutEngine::layoutTextOnLineOrPath(SVGInlineTextBox* textBox, cons
 
     // Main layout algorithm.
     const unsigned boxEndOffset = textBox->start() + textBox->len();
-    while (m_visualMetricsIterator.characterOffset() < boxEndOffset) {
+    while (!m_visualMetricsIterator.isAtEnd() && m_visualMetricsIterator.characterOffset() < boxEndOffset) {
         const SVGTextMetrics& visualMetrics = m_visualMetricsIterator.metrics();
         if (visualMetrics.isEmpty()) {
             m_visualMetricsIterator.next();