new functions and fixes

static/js/image-upload.js

@@ -9,6 +9,9 @@
 
 function clamp(value, min, max) { return Math.min(max, Math.max(min, value)); }
 function stem(name) { return name.replace(/\.[^.]+$/, "") || "image"; }
+function imageNeedsProcessing(width, height, aspect, maxSize) {
+  return aspect !== "original" || (maxSize > 0 && Math.max(width, height) > maxSize);
+}
 
 export async function prepareImageFile(file) {
   if (!file.type.startsWith("image/")) return file;
@@ -61,8 +64,15 @@ export async function prepareImageFile(file) {
   const result = new Promise(resolve => {
     dialog.addEventListener("close", () => { URL.revokeObjectURL(url); dialog.remove(); resolve(accepted); }, { once: true });
     dialog.querySelector("[data-apply]").addEventListener("click", async () => {
-      const box = cropBox(), maxSize = Number(sizeSelect.value), out = document.createElement("canvas");
-      if (aspectSelect.value === "original") {
+      const box = cropBox(), maxSize = Number(sizeSelect.value);
+      const wholeImage = aspectSelect.value === "original";
+      if (!imageNeedsProcessing(image.naturalWidth, image.naturalHeight, aspectSelect.value, maxSize)) {
+        accepted = file;
+        dialog.close();
+        return;
+      }
+      const out = document.createElement("canvas");
+      if (wholeImage) {
         const ratio = Math.min(1, maxSize ? maxSize / Math.max(image.naturalWidth, image.naturalHeight) : 1);
         out.width = Math.max(1, Math.round(image.naturalWidth * ratio)); out.height = Math.max(1, Math.round(image.naturalHeight * ratio));
         out.getContext("2d").drawImage(image, 0, 0, out.width, out.height);