Diff iterators

This refactors the diff output code so that an iterator object
can be used to traverse and generate the diffs, instead of just
the `foreach()` style with callbacks.  The code has been rearranged
so that the two styles can still share most functions.

This also replaces `GIT_REVWALKOVER` with `GIT_ITEROVER` and uses
that as a common error code for marking the end of iteration when
using a iterator style of object.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/submodule.c b/src/submodule.c
index a9de9ee6e..66f1f84b4 100644
--- a/src/submodule.c
+++ b/src/submodule.c
@@ -163,6 +163,7 @@ int git_submodule_foreach(
 		}
 
 		if (callback(sm, sm->name, payload)) {
+			giterr_clear();
 			error = GIT_EUSER;
 			break;
 		}