Initial stab at fixing diffs involving submodule changes

Author: thetwoj

git/cmd.py

@@ -67,7 +67,7 @@
 
 def handle_process_output(process, stdout_handler, stderr_handler,
                           finalizer=None, decode_streams=True):
-    """Registers for notifications to lean that process output is ready to read, and dispatches lines to
+    """Registers for notifications to learn that process output is ready to read, and dispatches lines to
     the respective line handlers.
     This function returns once the finalizer returns
 

git/diff.py

@@ -278,6 +278,14 @@ def __init__(self, repo, a_rawpath, b_rawpath, a_blob_id, b_blob_id, a_mode,
         if self.b_mode:
             self.b_mode = mode_str_to_int(self.b_mode)
 
+        # Determine whether this diff references a submodule, if it does then
+        # we need to overwrite "repo" to the corresponding submodule's repo instead
+        if repo and a_rawpath:
+            for submodule in repo.submodules:
+                if submodule.path == a_rawpath.decode("utf-8"):
+                    repo = submodule.module()
+                    break
+
         if a_blob_id is None or a_blob_id == self.NULL_HEX_SHA:
             self.a_blob = None
         else: