[FIX] otools-pending remove: crash when removing last pending merge

When the last pending PR was removed, the merges file was deleted
but the aggregator still tried to read it, causing a ConfigException.

Skip aggregation when the file has been removed (no merges left).

Author: ivantodorovich

odoo_tools/utils/pending_merge.py

@@ -687,7 +687,7 @@ def remove_pending(entity_url, aggregate=True):
 
     if not pending_merges_present and not patches:
         repo.abs_merges_path.unlink()
-    if aggregate:
+    elif aggregate:
         aggregator = repo.get_aggregator()
         aggregator.aggregate()
     return repo

tests/test_utils_pending_merge.py

@@ -260,6 +260,36 @@ def test_remove_pending_pr():
     assert merges == expected
 
 
+@pytest.mark.usefixtures("all_template_versions")
+def test_remove_pending_last_pr():
+    """Test removing the last pending PR deletes the merges file."""
+    name = "edi"
+    # Template with only one pending PR (besides the base branch)
+    tmpl = """
+../{ext_src_rel_path}/{repo_name}:
+    remotes:
+        camptocamp: git@github.com:camptocamp/{repo_name}.git
+        {org_name}: git@github.com:{org_name}/{repo_name}.git
+    target: camptocamp merge-branch-{pid}-master
+    merges:
+    - {org_name} 14.0
+    - {org_name} refs/pull/774/head
+"""
+    mock_pending_merge_repo_paths(name, tmpl=tmpl)
+    repo = Repo(name, path_check=False)
+    merges = repo.merges_config().get("merges", [])
+    assert merges == ["OCA 14.0", "OCA refs/pull/774/head"]
+    # Remove the only pending PR via the top-level function
+    # (which deletes the file when no PRs are left)
+    # Use aggregate=True (the default) to reproduce the bug
+    pm_utils.remove_pending(
+        "https://github.com/OCA/edi/pull/774",
+        aggregate=True,
+    )
+    # The merges file should have been removed
+    assert not repo.abs_merges_path.exists()
+
+
 # TODO: test all cases
 def __test_add_pending_commit_from_scratch():
     name = "edi"