FIX #3537 Disabling the legend based on the x-axis and hue values

seaborn/categorical.py

@@ -409,12 +409,10 @@ def _invert_scale(self, ax, data, vars=("x", "y")):
                     data[col] = inv(data[col])
 
     def _configure_legend(self, ax, func, common_kws=None, semantic_kws=None):
-
         if self.legend == "auto":
             show_legend = not self._redundant_hue and self.input_format != "wide"
         else:
             show_legend = bool(self.legend)
-
         if show_legend:
             self.add_legend_data(ax, func, common_kws, semantic_kws=semantic_kws)
             handles, _ = ax.get_legend_handles_labels()
@@ -3095,7 +3093,11 @@ def catplot(
         g._update_legend_data(ax)
         ax.legend_ = None
 
-    if legend and "hue" in p.variables and p.input_format == "long":
+    if legend == "auto":
+        show_legend = not p._redundant_hue and p.input_format != "wide"
+    else:
+        show_legend = bool(legend)
+    if show_legend:
         g.add_legend(title=p.variables.get("hue"), label_order=hue_order)
 
     if data is not None:

tests/test_categorical.py

@@ -3125,6 +3125,14 @@ def test_invalid_kind(self, long_df):
         with pytest.raises(ValueError, match="Invalid `kind`: 'wrong'"):
             catplot(long_df, kind="wrong")
 
+    def test_legend_with_auto(self):
+
+        g1 = catplot(self.df, x="g", y="y", hue="g", legend='auto')
+        assert g1._legend is None
+
+        g2 = catplot(self.df, x="g", y="y", hue="g", legend=True)
+        assert g2._legend is not None
+
 
 class TestBeeswarm: