handle git being in a detached head state when getting current commit

Author: jesopo

modules/info.py

@@ -4,11 +4,12 @@
 class Module(ModuleManager.BaseModule):
     @utils.hook("received.command.version")
     def version(self, event):
-        commit_hash = utils.git_commit(self.bot.directory)
+        commit = utils.git_commit(self.bot.directory)
 
         out = "Version: BitBot %s" % IRCBot.VERSION
-        if not commit_hash == None:
-            out = "%s (%s@%s)" % (out, branch, commit_hash)
+        if not commit == None:
+            branch, commit = commit
+            out = "%s (%s@%s)" % (out, branch or "", commit)
         event["stdout"].write(out)
 
     @utils.hook("received.command.source")

src/ModuleManager.py

@@ -272,9 +272,10 @@ def _load_module(self, bot: "IRCBot.Bot", definition: ModuleDefinition,
             for key, value in magic.get_exports():
                 context_exports.add(key, value)
 
-        current_commit = utils.git_commit(bot.directory)
+        branch, commit = utils.git_commit(bot.directory)
+
         return LoadedModule(definition.name, module_title, module_object,
-            context, import_name, definition.is_core, commit=current_commit)
+            context, import_name, definition.is_core, commit=commit)
 
     def load_module(self, bot: "IRCBot.Bot", definition: ModuleDefinition
             ) -> LoadedModule:

src/utils/__init__.py

@@ -127,17 +127,20 @@ def _wrap(func, q):
     else:
         raise out # type: ignore
 
-def git_commit(bot_directory: str) -> typing.Optional[str]:
+def git_commit(bot_directory: str
+        ) -> typing.Tuple[typing.Optional[str], typing.Optional[str]]:
     git_dir = os.path.join(bot_directory, ".git")
     head_filepath = os.path.join(git_dir, "HEAD")
     if os.path.isfile(head_filepath):
-        ref = None
         with open(head_filepath, "r") as head_file:
-            ref = head_file.readline().split(" ", 1)[1].strip()
-        branch = ref.rsplit("/", 1)[1]
-
-        ref_filepath = os.path.join(git_dir, ref)
-        if os.path.isfile(ref_filepath):
-            with open(ref_filepath, "r") as ref_file:
-                return ref_file.readline().strip()[:8]
-    return None
+            ref_line = head_file.readline().strip()
+            if not ref_line.startswith("ref: "):
+                return None, ref_line
+            else:
+                ref = ref_line.split(" ", 1)[1]
+                branch = ref.rsplit("/", 1)[1]
+
+                ref_filepath = os.path.join(git_dir, ref)
+                with open(ref_filepath, "r") as ref_file:
+                    return branch, ref_file.readline().strip()[:8]
+    return None, None