Avoid a deprecation warning from numpy 1.25 in crs._safe_pj_transform

lib/cartopy/crs.py

@@ -53,7 +53,16 @@ def _safe_pj_transform(src_crs, tgt_crs, x, y, z=None, trap=True):
     if z is None:
         z = np.zeros_like(x)
 
-    return transformer.transform(x, y, z, errcheck=trap)
+    with warnings.catch_warnings():
+        # pyproj implicitly converts size-1 arrays to scalars, which is
+        # deprecated in numpy 1.25, but *also* handles the future error
+        # see https://github.com/numpy/numpy/pull/10615
+        # and https://github.com/SciTools/cartopy/pull/2194
+        warnings.filterwarnings(
+            "ignore",
+            message="Conversion of an array with ndim > 0"
+        )
+        return transformer.transform(x, y, z, errcheck=trap)
 
 
 class Globe:

lib/cartopy/tests/test_crs.py

@@ -9,6 +9,7 @@
 import os
 from pathlib import Path
 import pickle
+import warnings
 
 import numpy as np
 from numpy.testing import assert_almost_equal
@@ -351,3 +352,13 @@ def test_projection__from_string():
 
 def test_crs__from_pyproj_crs():
     assert ccrs.CRS(pyproj.CRS("EPSG:4326")) == "EPSG:4326"
+
+
+def test_transform_point_no_warning():
+    # Make sure we aren't warning on single-point numpy arrays
+    # see https://github.com/SciTools/cartopy/pull/2194
+    p = ccrs.PlateCarree()
+    p2 = ccrs.Mercator()
+    with warnings.catch_warnings():
+        warnings.simplefilter("error")
+        p2.transform_point(1, 2, p)