do not mix nodata mask

CHANGES.md

@@ -1,4 +1,8 @@
 
+# 6.3.1 (2024-01-22)
+
+* When overriding **nodata**, do not mix mask and only use the provided nodata value
+
 # 6.3.0 (2024-01-16)
 
 * do not use `warpedVRT` when overwriting the dataset nodata value

rio_tiler/reader.py

@@ -238,7 +238,7 @@ def read(
 
             # if data has Nodata then we simply make sure the mask == the nodata
             if nodata is not None:
-                data.mask |= data == nodata
+                data.mask = data.data == nodata
 
         stats = []
         for ix in indexes:

tests/test_reader.py

@@ -33,6 +33,7 @@
 COG = os.path.join(os.path.dirname(__file__), "fixtures", "cog.tif")
 COG_SCALE = os.path.join(os.path.dirname(__file__), "fixtures", "cog_scale.tif")
 COG_CMAP = os.path.join(os.path.dirname(__file__), "fixtures", "cog_cmap.tif")
+COG_NODATA = os.path.join(os.path.dirname(__file__), "fixtures", "cog_nodata.tif")
 
 
 @pytest.fixture(autouse=True)
@@ -836,3 +837,14 @@ def test_part_align_transform(bounds, crs):
         # with the bounds greater than UL
         assert img.transform.c < bounds[0]
         assert img.transform.f > bounds[3]
+
+
+def test_nodata_orverride():
+    """Make sure notata override."""
+    with rasterio.open(COG_NODATA) as src_dst:
+        prev = reader.read(src_dst, max_size=100)
+        assert prev.mask[0, 0] == 0
+
+        prev = reader.read(src_dst, max_size=100, nodata=2720)
+        assert prev.mask[0, 0] == 255
+        assert not numpy.all(prev.mask)