FIX: Allow different colormap name from registered name

greglucas · greglucas · commit 4fbc57de266a · 2023-03-16T11:56:37.000-06:00
When registering a colormap you can use a different name than
the "cmap.name" attribute now. This will set the colormap based
on the registered name rather than cmap.name
diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
@@ -2180,9 +2180,13 @@ def set_cmap(cmap):
     matplotlib.cm.register_cmap
     matplotlib.cm.get_cmap
     """
+    # The name of the colormap may be different than the registered name.
+    # We want the registered name for the rc setting
+    name = getattr(cmap, "name", cmap)
+    # Run this through get_cmap to confirm this is a valid cmap before
+    # updating the rc parameters
     cmap = get_cmap(cmap)
-
-    rc('image', cmap=cmap.name)
+    rc('image', cmap=name)
     im = gci()
 
     if im is not None:
diff --git a/lib/matplotlib/tests/test_colors.py b/lib/matplotlib/tests/test_colors.py
@@ -1603,3 +1603,16 @@ def test_cm_set_cmap_error():
     bad_cmap = 'AardvarksAreAwkward'
     with pytest.raises(ValueError, match=bad_cmap):
         sm.set_cmap(bad_cmap)
+
+
+def test_set_cmap_mismatched_name():
+    cmap = matplotlib.colormaps["viridis"].copy()
+    # register it with different names
+    cmap.name = "test-cmap"
+    matplotlib.colormaps.register(name='wrong-cmap', cmap=cmap)
+
+    plt.set_cmap("wrong-cmap")
+    cmap_returned = plt.get_cmap("wrong-cmap")
+    assert cmap_returned == cmap
+    # The name of the cmap is test-cmap even though we requested wrong-cmap
+    assert cmap_returned.name == "test-cmap"
