MNT: Handle malformed input better

tacaswell · tacaswell · commit f132088abfe3 · 2020-04-27T01:00:21.000-04:00
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -1673,6 +1673,7 @@ def _process_layout(layout):
             return unique_ids, nested
 
         def _do_layout(gs, layout, unique_ids, nested):
+
             rows, cols = layout.shape
             output = dict()
 
@@ -1702,8 +1703,10 @@ def _do_layout(gs, layout, unique_ids, nested):
                         gs[slc], **{'label': str(name), **subplot_kw})
 
             for (j, k), nested_layout in nested.items():
-                if not all(len(r) for r in nested_layout):
-                    raise ValueError("All of the rows must be the same length")
+                if not all(len(r) == len(nested_layout[0])
+                           for r in nested_layout):
+                    raise ValueError(
+                        "All of the rows must be the same length.")
                 nested_layout = np.asarray(nested_layout, dtype=object)
                 rows, cols = nested_layout.shape
                 gs_n = gs[j, k].subgridspec(rows, cols, **gridspec_kw)
@@ -1716,7 +1719,7 @@ def _do_layout(gs, layout, unique_ids, nested):
                                      f"and the nested layout\n{nested_layout}")
                 output.update(nested_output)
             return output
-        if not all(len(r) for r in layout):
+        if not all(len(r) == len(layout[0]) for r in layout):
             raise ValueError("All of the rows must be the same length")
         layout = np.asarray(layout, dtype=object)
         rows, cols = layout.shape
diff --git a/lib/matplotlib/tests/test_figure.py b/lib/matplotlib/tests/test_figure.py
@@ -688,7 +688,10 @@ def test_single_str_input(self, fig_test, fig_ref, str_pattern):
          # This more specific test fails 1/3 times
          # "There are duplicate keys {.B., .A.} between the outer layout"
          "There are duplicate keys .* between the outer layout"
-         )
+         ),
+        ('AAA\nc\nBBB', 'All of the rows must be the same length'),
+        ([['A', [['B', 'C'], ['D']]], ['E', 'E']],
+         'All of the rows must be the same length'),
         ])
     def test_fail(self, x, match):
         fig = plt.figure()
