fix: read TIFF dimensions from raw IFD tags for pre-decode validation

UTIF.decode populates raw tag entries (t256/t257) but .width/.height
are only set after decodeImage. Read from raw tags so the pixel limit
guard works before the expensive decode step without rejecting valid
files.

Author: gpardhivvarma

packages/super-editor/src/core/super-converter/v3/handlers/wp/helpers/tiff-converter.js

@@ -90,15 +90,20 @@ export function convertTiffToPng(data) {
     const ifds = UTIF.decode(buffer);
     if (!ifds || ifds.length === 0) return null;
 
-    // Validate dimensions from IFD metadata before decoding pixel data
-    const { width, height } = ifds[0];
-    if (!width || !height || width * height > MAX_PIXEL_COUNT) return null;
+    // Validate dimensions from raw IFD tags before decoding pixel data.
+    // UTIF.decode populates tag entries (t256=ImageWidth, t257=ImageLength)
+    // but .width/.height are only set after decodeImage.
+    const ifdWidth = ifds[0].t256?.[0];
+    const ifdHeight = ifds[0].t257?.[0];
+    if (!ifdWidth || !ifdHeight || ifdWidth * ifdHeight > MAX_PIXEL_COUNT) return null;
 
     // Decode pixel data for the first page
     UTIF.decodeImage(buffer, ifds[0]);
     const rgba = UTIF.toRGBA8(ifds[0]);
     if (!rgba || rgba.length === 0) return null;
 
+    const { width, height } = ifds[0];
+
     // Render to canvas and export as PNG
     const canvas = createCanvas();
     if (!canvas) {

packages/super-editor/src/core/super-converter/v3/handlers/wp/helpers/tiff-converter.test.js

@@ -61,9 +61,10 @@ describe('tiff-converter', () => {
     });
 
     it('returns null for TIFF with dimensions exceeding pixel limit', () => {
-      // Mock utif2 to return oversized dimensions (100k × 10k = 1 billion pixels)
+      // Mock utif2 to return oversized dimensions via raw IFD tags
+      // (t256=ImageWidth, t257=ImageLength — 100k × 10k = 1 billion pixels)
       vi.doMock('utif2', () => ({
-        decode: () => [{ width: 100_000, height: 10_000 }],
+        decode: () => [{ t256: [100_000], t257: [10_000] }],
         decodeImage: () => undefined,
         toRGBA8: () => new Uint8Array(4),
       }));