Ensure `#[getter]` doc is exposed as the `__doc__` of the descriptor

src/class/methods.rs

@@ -97,6 +97,9 @@ impl PyGetterDef {
                 .expect("Method name must not contain NULL byte")
                 .into_raw();
         }
+        if dst.doc.is_null() {
+            dst.doc = self.doc.as_ptr() as *mut libc::c_char;
+        }
         dst.get = Some(self.meth);
     }
 }

tests/test_getter_setter.rs

@@ -1,4 +1,5 @@
 use pyo3::prelude::*;
+use pyo3::types::IntoPyDict;
 use std::isize;
 
 #[macro_use]
@@ -16,6 +17,7 @@ impl ClassWithProperties {
     }
 
     #[getter(DATA)]
+    /// a getter for data
     fn get_data(&self) -> PyResult<i32> {
         Ok(self.num)
     }
@@ -38,6 +40,9 @@ fn class_with_properties() {
     py_run!(py, inst, "inst.DATA = 20");
     py_run!(py, inst, "assert inst.get_num() == 20");
     py_run!(py, inst, "assert inst.get_num() == inst.DATA");
+
+    let d = [("C", py.get_type::<ClassWithProperties>())].into_py_dict(py);
+    py.run("assert C.DATA.__doc__ == 'a getter for data'", None, Some(d)).unwrap();
 }
 
 #[pyclass]