MAINT: move license_file property to wheel builder

The license.file field in the metadata is also already an absolute
path, there is no need to concatenate it to the source directory.
Doing so multiple times is even less necessary.

Author: dnicolodi

mesonpy/__init__.py

@@ -311,6 +311,13 @@ def distinfo_dir(self) -> str:
     def data_dir(self) -> str:
         return f'{self.basename}.data'
 
+    @property
+    def _license_file(self) -> Optional[pathlib.Path]:
+        license_ = self._metadata.license
+        if license_:
+            return license_.file
+        return None
+
     @cached_property
     def is_pure(self) -> bool:
         """Is the wheel "pure" (architecture independent)?"""
@@ -443,11 +450,8 @@ def _wheel_write_metadata(self, whl: mesonpy._wheelfile.WheelFile) -> None:
             whl.writestr(f'{self.distinfo_dir}/entry_points.txt', self.entrypoints_txt)
 
         # add license (see https://github.com/mesonbuild/meson-python/issues/88)
-        if self._project.license_file:
-            whl.write(
-                self._source_dir / self._project.license_file,
-                f'{self.distinfo_dir}/{os.path.basename(self._project.license_file)}',
-            )
+        if self._license_file:
+            whl.write(self._license_file, f'{self.distinfo_dir}/{os.path.basename(self._license_file)}')
 
     def build(self, directory: Path) -> pathlib.Path:
         # ensure project is built
@@ -839,13 +843,6 @@ def version(self) -> str:
         """Project version."""
         return str(self._metadata.version)
 
-    @property
-    def license_file(self) -> Optional[pathlib.Path]:
-        license_ = self._metadata.license
-        if license_ and license_.file:
-            return pathlib.Path(license_.file)
-        return None
-
     @property
     def is_pure(self) -> bool:
         """Is the wheel "pure" (architecture independent)?"""