Patchwork [3,of,5] rust-cpython: require GIL to borrow immutable reference from PySharedRefCell

diff --git a/rust/hg-cpython/src/dirstate/dirs_multiset.rs b/rust/hg-cpython/src/dirstate/dirs_multiset.rs
--- a/rust/hg-cpython/src/dirstate/dirs_multiset.rs
+++ b/rust/hg-cpython/src/dirstate/dirs_multiset.rs
@@ -100,7 +100,7 @@  py_class!(pub class Dirs |py| {
     }
 
     def __contains__(&self, item: PyObject) -> PyResult<bool> {
-        Ok(self.inner(py).borrow().contains(HgPath::new(
+        Ok(self.inner_shared(py).borrow().contains(HgPath::new(
             item.extract::<PyBytes>(py)?.data(py).as_ref(),
         )))
     }
diff --git a/rust/hg-cpython/src/dirstate/dirstate_map.rs b/rust/hg-cpython/src/dirstate/dirstate_map.rs
--- a/rust/hg-cpython/src/dirstate/dirstate_map.rs
+++ b/rust/hg-cpython/src/dirstate/dirstate_map.rs
@@ -64,7 +64,7 @@  py_class!(pub class DirstateMap |py| {
         default: Option<PyObject> = None
     ) -> PyResult<Option<PyObject>> {
         let key = key.extract::<PyBytes>(py)?;
-        match self.inner(py).borrow().get(HgPath::new(key.data(py))) {
+        match self.inner_shared(py).borrow().get(HgPath::new(key.data(py))) {
             Some(entry) => {
                 // Explicitly go through u8 first, then cast to
                 // platform-specific `c_char`.
@@ -179,7 +179,7 @@  py_class!(pub class DirstateMap |py| {
     // TODO share the reference
     def nonnormalentries(&self) -> PyResult<PyObject> {
         let (non_normal, other_parent) =
-            self.inner(py).borrow().non_normal_other_parent_entries();
+            self.inner_shared(py).borrow().non_normal_other_parent_entries();
 
         let locals = PyDict::new(py);
         locals.set_item(
@@ -290,18 +290,18 @@  py_class!(pub class DirstateMap |py| {
     }
 
     def __len__(&self) -> PyResult<usize> {
-        Ok(self.inner(py).borrow().len())
+        Ok(self.inner_shared(py).borrow().len())
     }
 
     def __contains__(&self, key: PyObject) -> PyResult<bool> {
         let key = key.extract::<PyBytes>(py)?;
-        Ok(self.inner(py).borrow().contains_key(HgPath::new(key.data(py))))
+        Ok(self.inner_shared(py).borrow().contains_key(HgPath::new(key.data(py))))
     }
 
     def __getitem__(&self, key: PyObject) -> PyResult<PyObject> {
         let key = key.extract::<PyBytes>(py)?;
         let key = HgPath::new(key.data(py));
-        match self.inner(py).borrow().get(key) {
+        match self.inner_shared(py).borrow().get(key) {
             Some(entry) => {
                 // Explicitly go through u8 first, then cast to
                 // platform-specific `c_char`.
@@ -350,7 +350,7 @@  py_class!(pub class DirstateMap |py| {
         Dirs::from_inner(
             py,
             DirsMultiset::from_dirstate(
-                &self.inner(py).borrow(),
+                &self.inner_shared(py).borrow(),
                 Some(EntryState::Removed),
             ),
         )
@@ -361,7 +361,7 @@  py_class!(pub class DirstateMap |py| {
         Dirs::from_inner(
             py,
             DirsMultiset::from_dirstate(
-                &self.inner(py).borrow(),
+                &self.inner_shared(py).borrow(),
                 None,
             ),
         )
@@ -370,7 +370,7 @@  py_class!(pub class DirstateMap |py| {
     // TODO all copymap* methods, see docstring above
     def copymapcopy(&self) -> PyResult<PyDict> {
         let dict = PyDict::new(py);
-        for (key, value) in self.inner(py).borrow().copy_map.iter() {
+        for (key, value) in self.inner_shared(py).borrow().copy_map.iter() {
             dict.set_item(
                 py,
                 PyBytes::new(py, key.as_ref()),
@@ -382,7 +382,7 @@  py_class!(pub class DirstateMap |py| {
 
     def copymapgetitem(&self, key: PyObject) -> PyResult<PyBytes> {
         let key = key.extract::<PyBytes>(py)?;
-        match self.inner(py).borrow().copy_map.get(HgPath::new(key.data(py))) {
+        match self.inner_shared(py).borrow().copy_map.get(HgPath::new(key.data(py))) {
             Some(copy) => Ok(PyBytes::new(py, copy.as_ref())),
             None => Err(PyErr::new::<exc::KeyError, _>(
                 py,
@@ -395,12 +395,12 @@  py_class!(pub class DirstateMap |py| {
     }
 
     def copymaplen(&self) -> PyResult<usize> {
-        Ok(self.inner(py).borrow().copy_map.len())
+        Ok(self.inner_shared(py).borrow().copy_map.len())
     }
     def copymapcontains(&self, key: PyObject) -> PyResult<bool> {
         let key = key.extract::<PyBytes>(py)?;
         Ok(self
-            .inner(py)
+            .inner_shared(py)
             .borrow()
             .copy_map
             .contains_key(HgPath::new(key.data(py))))
@@ -412,7 +412,7 @@  py_class!(pub class DirstateMap |py| {
     ) -> PyResult<Option<PyObject>> {
         let key = key.extract::<PyBytes>(py)?;
         match self
-            .inner(py)
+            .inner_shared(py)
             .borrow()
             .copy_map
             .get(HgPath::new(key.data(py)))
diff --git a/rust/hg-cpython/src/ref_sharing.rs b/rust/hg-cpython/src/ref_sharing.rs
--- a/rust/hg-cpython/src/ref_sharing.rs
+++ b/rust/hg-cpython/src/ref_sharing.rs
@@ -136,7 +136,7 @@  impl<T> PySharedRefCell<T> {
         }
     }
 
-    pub fn borrow(&self) -> Ref<T> {
+    pub fn borrow<'a>(&'a self, _py: Python<'a>) -> Ref<'a, T> {
         // py_shared_state isn't involved since
         // - inner.borrow() would fail if self is mutably borrowed,
         // - and inner.borrow_mut() would fail while self is borrowed.
@@ -180,7 +180,7 @@  impl<'a, T> PySharedRef<'a, T> {
     }
 
     pub fn borrow(&self) -> Ref<T> {
-        self.data.borrow()
+        self.data.borrow(self.py)
     }
 
     pub fn borrow_mut(&self) -> PyResult<PyRefMut<'a, T>> {