Engine: fix bug when caching from process with nested outputs

aiida/engine/processes/process.py

@@ -582,11 +582,13 @@ def _create_and_setup_db_record(self) -> Union[int, UUID]:
                     for entry in self.node.base.links.get_outgoing(link_type=LinkType.RETURN):
                         if entry.link_label.endswith(f'_{entry.node.pk}'):
                             continue
-                        self.out(entry.link_label, entry.node)
+                        label = entry.link_label.replace(PORT_NAMESPACE_SEPARATOR, self.spec().namespace_separator)
+                        self.out(label, entry.node)
                     # This is needed for CalcJob. In that case, the outputs are
                     # returned regardless of whether they end in '_pk'
                     for entry in self.node.base.links.get_outgoing(link_type=LinkType.CREATE):
-                        self.out(entry.link_label, entry.node)
+                        label = entry.link_label.replace(PORT_NAMESPACE_SEPARATOR, self.spec().namespace_separator)
+                        self.out(label, entry.node)
             except exceptions.ModificationNotAllowed:
                 # The calculation was already stored
                 pass

tests/engine/processes/test_caching.py

@@ -0,0 +1,37 @@
+# -*- coding: utf-8 -*-
+"""Test the caching functionality for a :class:`aiida.engine.processes.process.Process`."""
+from aiida.engine import Process, run
+from aiida.manage import enable_caching
+from aiida.orm import CalcJobNode, Int
+
+
+class NestedOutputsProcess(Process):
+    """Process with dynamic nested output namespace."""
+
+    _node_class = CalcJobNode
+
+    @classmethod
+    def define(cls, spec):
+        super().define(spec)
+        spec.input('a')
+        spec.output_namespace('nested', dynamic=True)
+
+    def run(self):
+        self.out('nested', {'a': self.inputs.a + 2})
+
+
+def test_caching_nested_output_namespace():
+    """Test that caching from a process with a nested output namespace works."""
+    _, node_original = run.get_node(NestedOutputsProcess, a=Int(1))
+    assert not node_original.is_created_from_cache
+
+    with enable_caching():
+        _, node_clone = run.get_node(NestedOutputsProcess, a=Int(1))
+
+    assert node_clone.is_created_from_cache
+    assert node_clone.get_cache_source() == node_original.uuid
+
+    outputs = node_clone.get_outgoing().nested()
+    assert list(outputs.keys()) == ['nested']
+    assert list(outputs['nested'].keys()) == ['a']
+    assert isinstance(outputs['nested']['a'], Int)