Ensure stops have the correct keyframe associated.

Try to recover from unpatched svg icon with clearer error message.

property-loader/src/main/java/com/github/weisj/darklaf/icons/DarkSVGIcon.java

@@ -131,7 +131,27 @@ public class DarkSVGIcon implements DerivableIcon<DarkSVGIcon>, RotateIcon, Seri
     public Image createImage(final Dimension size) {
         ensureLoaded(false);
         icon.setPreferredSize(size);
-        return icon.getImage();
+        try {
+            return icon.getImage();
+        } catch (RuntimeException e) {
+            if (!(this instanceof ThemedSVGIcon)) {
+                IconColorMapper.patchColors(icon);
+                Image img = icon.getImage();
+                /*
+                 * If we get to here the issue was that the icon hasn't been patched because it isn't loaded as a themed
+                 * svg icon.
+                 */
+                LOGGER.severe("Icon '" + getName() + "' that defines custom colors isn't loaded as themed icon.");
+                return img;
+            }
+            throw e;
+        }
+    }
+
+    private String getName() {
+        String name = uri.toASCIIString();
+        name = name.substring(Math.min(name.length() - 1, name.lastIndexOf('/') + 1));
+        return name;
     }
 
     protected void ensureImageLoaded(final Component c, final double rotation) {

property-loader/src/main/java/com/github/weisj/darklaf/icons/IconColorMapper.java

@@ -158,15 +158,15 @@ public final class IconColorMapper {
                                                               final float opacity) throws SVGElementException {
         LinearGradient grad = new LinearGradient();
         grad.addAttribute("id", AnimationElement.AT_XML, name);
-        if (opacityKey != null) {
+        if (opacityKey != null && !opacityKey.isEmpty()) {
             grad.addAttribute("opacity", AnimationElement.AT_XML, opacityKey);
         }
-        if (fallbacks != null) {
+        if (fallbacks != null && !fallbacks.getStringValue().isEmpty()) {
             grad.addAttribute(fallbacks.getName(), AnimationElement.AT_XML, fallbacks.getStringValue());
         }
         return new Pair<>(grad, () -> {
-            Stop stop1 = new Stop();
-            Stop stop2 = new Stop();
+            SolidStop stop1 = new SolidStop();
+            SolidStop stop2 = new SolidStop();
             String color = toHexString(c);
             try {
                 stop1.addAttribute("stop-color", AnimationElement.AT_XML, color);
@@ -177,9 +177,11 @@ public final class IconColorMapper {
                     stop1.addAttribute("stop-opacity", AnimationElement.AT_XML, String.valueOf(opacity));
                     stop2.addAttribute("stop-opacity", AnimationElement.AT_XML, String.valueOf(opacity));
                 }
-                grad.loaderAddChild(null, stop1);
-                grad.loaderAddChild(null, stop2);
-            } catch (SVGElementException e) {
+                stop1.build();
+                stop2.build();
+                grad.appendStop(stop1);
+                grad.appendStop(stop2);
+            } catch (SVGException e) {
                 e.printStackTrace();
             }
         });
@@ -188,4 +190,12 @@ public final class IconColorMapper {
     private static String toHexString(final Color color) {
         return "#" + ColorUtil.toHex(color);
     }
+
+    private static class SolidStop extends Stop {
+
+        @Override
+        public void build() throws SVGException {
+            super.build();
+        }
+    }
 }

property-loader/src/main/java/com/github/weisj/darklaf/icons/ThemedSVGIcon.java

@@ -24,7 +24,6 @@
  */
 package com.github.weisj.darklaf.icons;
 
-import java.awt.*;
 import java.net.URI;
 
 /**