element.py: fix init_workspace for multiple sourcesraoul/440-fix

Noticed a mistake that got into !1214, so only the last source
gets initialised in a workspace. Added a test for this.

2 files changed, 30 insertions, 5 deletions

diff --git a/buildstream/element.py b/buildstream/element.py
index 8c507b768..c652015e4 100644
--- a/buildstream/element.py
+++ b/buildstream/element.py
@@ -1993,12 +1993,8 @@ class Element(Plugin):
         os.makedirs(context.builddir, exist_ok=True)
         with utils._tempdir(dir=context.builddir, prefix='workspace-{}'
                             .format(self.normal_name)) as temp:
-            last_source = None
             for source in self.sources():
-                last_source = source
-
-            if last_source:
-                last_source._init_workspace(temp)
+                source._init_workspace(temp)
 
             # Now hardlink the files into the workspace target.
             utils.link_files(temp, workspace.get_absolute_path())
diff --git a/tests/frontend/workspace.py b/tests/frontend/workspace.py
index 1db23ccc4..0f5d73db8 100644
--- a/tests/frontend/workspace.py
+++ b/tests/frontend/workspace.py
@@ -1231,6 +1231,35 @@ def test_external_list(cli, datafiles, tmpdir_factory):
     result.assert_success()
 
 
+@pytest.mark.datafiles(DATA_DIR)
+def test_multisource_workspace(cli, datafiles, tmpdir):
+    # checks that if an element has multiple sources, then the opened workspace
+    # will contain them
+    project = str(datafiles)
+    element_name = "multisource.bst"
+    element = {
+        'kind': 'import',
+        'sources': [{
+            'kind': 'local',
+            'path': 'files/bin-files'
+        }, {
+            'kind': 'local',
+            'path': 'files/dev-files'
+        }]
+    }
+    element_path = os.path.join(project, 'elements', element_name)
+    _yaml.dump(element, element_path)
+
+    workspace_dir = os.path.join(str(tmpdir), 'multisource')
+    res = cli.run(project=project,
+                  args=['workspace', 'open', 'multisource.bst',
+                        '--directory', workspace_dir])
+    res.assert_success()
+
+    directories = os.listdir(os.path.join(workspace_dir, 'usr'))
+    assert 'bin' in directories and 'include' in directories
+
+
 # This strange test tests against a regression raised in issue #919,
 # where opening a workspace on a runtime dependency of a build only
 # dependency causes `bst build` to not build the specified target