Fix cgmanifest.json generating script (#2770)

* Fix protobuf submodule name

* Workaround pygit2 bug

.gitmodules

@@ -1,4 +1,4 @@
-[submodule "external/protobuf"]
+[submodule "cmake/external/protobuf"]
 	path = cmake/external/protobuf
 	url = https://github.com/google/protobuf.git
 [submodule "cmake/external/googletest"]

tools/python/get_submodules.py

@@ -1,12 +1,44 @@
-import pygit2
+from operator import attrgetter
+from pathlib import Path
 import argparse
+import configparser
 import json
+import re
+
+import pygit2
+
 
 def format_component(submod):
-    return {"component":{"type":"git","git":{"commitHash":str(submod.head_id), "repositoryUrl":str(submod.url)}}}
+    return {"component": {"type": "git", "git": {"commitHash": str(submod.head_id), "repositoryUrl": submod.url}}}
+
+def lookup_submodule(repo, submodule_path):
+    submodule = repo.lookup_submodule(submodule_path)
+    try:
+        # Some submodules have names which don't correspond to the actual path in the repo
+        # (e.g. 'git submodule init' was called with the --name option, or the submodule
+        # was moved and the old name was kept). listall_submodules() returns submodule paths,
+        # but pygit up to 1.0.1 requires the submodule name (not the path) in lookup_submodule
+        # to be able to access the URL and other properties.
+        # This seems to be a bug in pygit2, since its documentation says the submodules can
+        # be opened by path.
+        # If accessing the URL throws a RuntimeError, we get the submodule name manually from
+        # .gitmodules.
+        submodule.url
+        return submodule
+    except RuntimeError:
+        pass
+
+    config = configparser.ConfigParser()
+    config.read(Path(repo.workdir, '.gitmodules'))
+    for section in config.sections():
+        if config[section]['path'] == submodule_path:
+            name = re.fullmatch('submodule "(.*)"', section).group(1)
+            submodule = repo.lookup_submodule(name)
+            return submodule
+    raise NotImplementedError()  # should not be reached
 
 def process_component(repo):
-    return [repo.lookup_submodule(submod) for submod in repo.listall_submodules()]
+    return [lookup_submodule(repo, submod) for submod in repo.listall_submodules()]
 
 def recursive_process(base_repo):
     processed_subs = []
@@ -24,10 +56,9 @@ def main(repo_path, output_file):
     with open(output_file, 'w') as f:
         json.dump(registrations, f, indent=4, sort_keys=True)
 
-if __name__=="__main__":
+if __name__ == "__main__":
     parser = argparse.ArgumentParser()
     parser.add_argument("base_repository", help="path to base repository to get registrations for.")
     parser.add_argument("-o", "--output", help="output file name.", default="cgmanifest.json")
     args = parser.parse_args()
     main(args.base_repository, args.output)
-