The a_path and b_path cannot reliably be read from the first diff lineas it's ambiguous.  From the git-diff manpage:  > The a/ and b/ filenames are the same unless rename/copy is involved.  > Especially, **even for a creation or a deletion**, /dev/null is not  > used in place of the a/ or b/ filenames.This patch changes the a_path and b_path detection to read it from themore reliable locations further down the diff headers.  Two use casesare fixed by this:  - As the man page snippet above states, for new/deleted files the a    or b path will now be properly None.  - File names with spaces in it are now properly parsed.Working on this patch, I realized the --- and +++ lines really belong tothe diff header, not the diff contents.  This means that when parsingthe patch format, the --- and +++ will now be swallowed, and not end upanymore as part of the diff contents.  The diff contents now alwaysstart with an @@ line.This may be a breaking change for some users that rely on thisbehaviour.  However, those users could now access that information morereliably via the normal Diff properties a_path and b_path now.

This makes sure we're not matching a \n here by accident.  It's nowalmost the same as the original that used \S+, except that spaces arenot eaten at the end of the string (for files that end in a space).

When both old/new mode and rename from/to lines are found, they willappear in different order.