try, try again

libraries/shared/src/shared/Storage.cpp

@@ -39,9 +39,11 @@ StoragePointer Storage::toFileStorage(const QString& filename) const {
 }
 
 MemoryStorage::MemoryStorage(size_t size, const uint8_t* data) : _size(size) {
-    // alloc smallest number of 4-byte chunks that will cover size bytes.  The buffer is padded out to a multiple
-    // of 4 to force an alignment that glTextureSubImage2D can later use.
-    _data.resize((size + 3) & ~0x3);
+    // we end up calling glCompressedTextureSubImage2D with this, and the rows of the image are expected
+    // to be word aligned.  This is fine in all cases except for 1x1 images and 2x2 images.  For 1x1,
+    // there is only one row, so the problem is avoided.  For 2x2, we add 2 extra bytes so there's
+    // room for the second row.
+    _data.resize(size == 4 ? 6 : size);
     if (data) {
         memcpy(_data.data(), data, size);
     }