#4201 use the same options for all encoding functions

cloning the options later meant that may_use_scrolling tagged the image with the boolean 'scroll' to indicate the scroll detection had already been used,
but the flag was later lost and scroll detection would run again in some cases, comparing the current image with itself..

xpra/server/window/compress.py

@@ -2646,7 +2646,8 @@ def nodata(msg, *args) -> None:
         if self.suspended:
             return nodata("suspended")
         start = monotonic()
-        if SCROLL_ALL and self.may_use_scrolling(image, options):
+        tdoptions = typedict(options)
+        if SCROLL_ALL and self.may_use_scrolling(image, tdoptions):
             return nodata("used scrolling instead")
         end = monotonic()
         log("scroll detection took %ims", 1000*(end-start))
@@ -2671,7 +2672,6 @@ def nodata(msg, *args) -> None:
             if self.is_cancelled(sequence):
                 return nodata("cancelled")
             raise RuntimeError(f"BUG: no encoder found for {coding!r} with options={options}")
-        tdoptions = typedict(options)
         try:
             ret = encoder(coding, image, tdoptions)
         except (TypeError, RuntimeError) as e: