Handle channel banner load failures

js/channelProfile.js

@@ -164,9 +164,6 @@ function preloadBannerImage(url) {
     if ("referrerPolicy" in img && !img.referrerPolicy) {
       img.referrerPolicy = "no-referrer";
     }
-    if ("crossOrigin" in img && !img.crossOrigin) {
-      img.crossOrigin = "anonymous";
-    }
     img.onload = () => {
       resolve(url);
     };
@@ -207,6 +204,43 @@ function setBannerVisual(el, url) {
   }
 }
 
+function ensureBannerFallbackHandler(bannerEl) {
+  if (!bannerEl) {
+    return;
+  }
+
+  const tagName = bannerEl.tagName ? bannerEl.tagName.toLowerCase() : "";
+  if (tagName !== "img") {
+    return;
+  }
+
+  if (bannerEl.dataset.bannerFallbackAttached === "true") {
+    return;
+  }
+
+  const handleError = () => {
+    const fallbackAttr =
+      (typeof bannerEl.dataset?.fallbackSrc === "string"
+        ? bannerEl.dataset.fallbackSrc.trim()
+        : "") ||
+      bannerEl.getAttribute("data-fallback-src") ||
+      "";
+    const fallbackSrc = fallbackAttr || FALLBACK_CHANNEL_BANNER;
+
+    const activeSrc = bannerEl.currentSrc || bannerEl.src || "";
+    if (activeSrc) {
+      channelBannerImageCache.delete(activeSrc);
+    }
+
+    if (fallbackSrc && bannerEl.src !== fallbackSrc) {
+      bannerEl.src = fallbackSrc;
+    }
+  };
+
+  bannerEl.addEventListener("error", handleError, { passive: true });
+  bannerEl.dataset.bannerFallbackAttached = "true";
+}
+
 function getChannelZapButton() {
   if (cachedZapButton && !document.body.contains(cachedZapButton)) {
     cachedZapButton = null;
@@ -2843,6 +2877,8 @@ function applyChannelProfileMetadata({
       bannerEl.setAttribute("data-fallback-src", fallbackSrc);
     }
 
+    ensureBannerFallbackHandler(bannerEl);
+
     if (!normalized.banner) {
       setBannerVisual(bannerEl, fallbackSrc);
     } else {

views/channel-profile.html

@@ -9,7 +9,6 @@
       alt="Banner"
       loading="lazy"
       referrerpolicy="no-referrer"
-      crossorigin="anonymous"
       data-fallback-src="assets/jpg/bitvid.jpg"
     />
     <div class="absolute inset-0 rounded-lg bg-black bg-opacity-50"></div>