element.py: Compute whether an element is cached only on `is_cached`

This removes the early call to get whether sources are locally cached
in `_update_source_state` by delegating it to the call of `is_cached`.

Once it is cached, the element is assumed to stay that way for the
duration of the pipeline, we can therefore cache the result once it is
true.

Also remove `Consistency.IS_CACHED`, which is not used anywhere else.

1 files changed, 6 insertions, 2 deletions

diff --git a/tests/sources/git.py b/tests/sources/git.py
index d6f9cb223..25976ffca 100644
--- a/tests/sources/git.py
+++ b/tests/sources/git.py
@@ -499,7 +499,9 @@ def test_unlisted_submodule(cli, tmpdir, datafiles, fail):
         result.assert_main_error(ErrorDomain.PLUGIN, "git:unlisted-submodule")
     else:
         result.assert_success()
-        assert "git:unlisted-submodule" in result.stderr
+        # We have cached things internally and successfully. Therefore, the plugin
+        # is not involved in checking whether the cache is correct or not.
+        assert "git:unlisted-submodule" not in result.stderr
 
 
 @pytest.mark.skipif(HAVE_GIT is False, reason="git is not available")
@@ -613,7 +615,9 @@ def test_invalid_submodule(cli, tmpdir, datafiles, fail):
         result.assert_main_error(ErrorDomain.PLUGIN, "git:invalid-submodule")
     else:
         result.assert_success()
-        assert "git:invalid-submodule" in result.stderr
+        # We have cached things internally and successfully. Therefore, the plugin
+        # is not involved in checking whether the cache is correct or not.
+        assert "git:invalid-submodule" not in result.stderr
 
 
 @pytest.mark.skipif(HAVE_GIT is False, reason="git is not available")