Update diff to use iterators

This is a major reorganization of the diff code.  This changes
the diff functions to use the iterators for traversing the
content.  This allowed a lot of code to be simplified.  Also,
this moved the functions relating to outputting a diff into a
new file (diff_output.c).

This includes a number of other changes - adding utility
functions, extending iterators, etc. plus more tests for the
diff code.  This also takes the example diff.c program much
further in terms of emulating git-diff command line options.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/iterator.h b/src/iterator.h
index ac30b4ded..aa78c9f29 100644
--- a/src/iterator.h
+++ b/src/iterator.h
@@ -23,6 +23,7 @@ struct git_iterator {
 	int (*current)(git_iterator *, const git_index_entry **);
 	int (*at_end)(git_iterator *);
 	int (*advance)(git_iterator *, const git_index_entry **);
+	int (*reset)(git_iterator *);
 	void (*free)(git_iterator *);
 };
 
@@ -60,6 +61,11 @@ GIT_INLINE(int) git_iterator_advance(
 	return iter->advance(iter, entry);
 }
 
+GIT_INLINE(int) git_iterator_reset(git_iterator *iter)
+{
+	return iter->reset(iter);
+}
+
 GIT_INLINE(void) git_iterator_free(git_iterator *iter)
 {
 	iter->free(iter);