Write custom sdist command for basemap

We need to do this because we are using `data_files` to inject the
DLL when building the wheels for Windows, but this DLL should never
be included in a source distribution.

Author: molinav

packages/basemap/setup.py

@@ -10,6 +10,7 @@
 import warnings
 from setuptools import setup
 from setuptools import find_packages
+from setuptools.command.sdist import sdist
 from setuptools.dist import Distribution
 from setuptools.extension import Extension
 
@@ -42,6 +43,18 @@ def checkversion(directory):
     return version
 
 
+class basemap_sdist(sdist):
+    """Custom `sdist` so that it will not pack DLLs on Windows if present."""
+
+    def finalize_options(self):
+        """Call `finalize_options` after cleaning `data_files` and reset."""
+
+        orig_data_files = self.distribution.data_files
+        self.distribution.data_files = []
+        sdist.finalize_options(self)
+        self.distribution.data_files = orig_data_files
+
+
 # Initialise include and library dirs.
 include_dirs = []
 library_dirs = []
@@ -98,7 +111,7 @@ def checkversion(directory):
     if os.name == "nt":
         # On Windows:
         # - DLLs get installed under `bin`.
-        # - We need to inject the DLL in the wheel using `data_files`.
+        # - We need to inject later the DLL in the wheel using `data_files`.
         # - We do not use `runtime_library_dirs` as workaround for a
         #   `distutils` bug (http://bugs.python.org/issue2437).
         library_dirs.append(os.path.join(geos_installdir, "bin"))
@@ -218,6 +231,9 @@ def checkversion(directory):
         "doc":
             doc_requires,
     },
+    "cmdclass": {
+        "sdist": basemap_sdist,
+    },
     "project_urls": {
         "Bug Tracker":
             "https://github.com/matplotlib/basemap/issues",