Enable stats on git_index_read_tree.

Replace with the contents of 
git_index_read_tree_with_stats() and improve
documentation comments.

include/git2/index.h

@@ -336,18 +336,6 @@ GIT_EXTERN(const git_index_entry_unmerged *) git_index_get_unmerged_byindex(git_
 GIT_EXTERN(int) git_index_entry_stage(const git_index_entry *entry);
 
 /**
- * Read a tree into the index file
- *
- * The current index contents will be replaced by the specified tree.
- *
- * @param index an existing index object
- * @param tree tree to read
- * @return 0 or an error code
- */
-GIT_EXTERN(int) git_index_read_tree(git_index *index, git_tree *tree);
-
-
-/**
  * Read a tree into the index file with stats
  *
  * The current index contents will be replaced by the specified tree. The total
@@ -355,10 +343,10 @@ GIT_EXTERN(int) git_index_read_tree(git_index *index, git_tree *tree);
  *
  * @param index an existing index object
  * @param tree tree to read
- * @param stats structure that receives the total node count
+ * @param stats structure that receives the total node count (may be NULL)
  * @return 0 or an error code
  */
-GIT_EXTERN(int) git_index_read_tree_with_stats(git_index *index, git_tree *tree, git_indexer_stats *stats);
+GIT_EXTERN(int) git_index_read_tree(git_index *index, git_tree *tree, git_indexer_stats *stats);
 
 /** @} */
 GIT_END_DECL

src/checkout.c

@@ -191,7 +191,7 @@ int git_checkout_head(git_repository *repo, git_checkout_opts *opts, git_indexer
 	if (!git_repository_head_tree(&tree, repo)) {
 		git_index *idx;
 		if (!(retcode = git_repository_index(&idx, repo))) {
-			if (!(retcode = git_index_read_tree_with_stats(idx, tree, stats))) {
+			if (!(retcode = git_index_read_tree(idx, tree, stats))) {
 				retcode = git_tree_walk(tree, checkout_walker, GIT_TREEWALK_POST, &payload);
 			}
 			git_index_free(idx);

src/index.c

@@ -1020,7 +1020,7 @@ static int read_tree_cb(const char *root, const git_tree_entry *tentry, void *da
 	return 0;
 }
 
-int git_index_read_tree_with_stats(git_index *index, git_tree *tree, git_indexer_stats *stats)
+int git_index_read_tree(git_index *index, git_tree *tree, git_indexer_stats *stats)
 {
 	git_indexer_stats dummy_stats;
 	read_tree_data rtd = {index, NULL};
@@ -1033,8 +1033,3 @@ int git_index_read_tree_with_stats(git_index *index, git_tree *tree, git_indexer
 
 	return git_tree_walk(tree, read_tree_cb, GIT_TREEWALK_POST, &rtd);
 }
-
-int git_index_read_tree(git_index *index, git_tree *tree)
-{
-	return git_index_read_tree_with_stats(index, tree, NULL);
-}

src/reset.c

@@ -80,7 +80,7 @@ int git_reset(
 		goto cleanup;
 	}
 
-	if (git_index_read_tree(index, tree) < 0) {
+	if (git_index_read_tree(index, tree, NULL) < 0) {
 		giterr_set(GITERR_INDEX, "%s - Failed to update the index.", ERROR_MSG);
 		goto cleanup;
 	}

tests-clar/index/read_tree.c

@@ -33,7 +33,7 @@ void test_index_read_tree__read_write_involution(void)
 
 	/* read-tree */
 	git_tree_lookup(&tree, repo, &expected);
-	cl_git_pass(git_index_read_tree(index, tree));
+	cl_git_pass(git_index_read_tree(index, tree, NULL));
 	git_tree_free(tree);
 
 	cl_git_pass(git_tree_create_fromindex(&tree_oid, index));

tests-clar/status/worktree.c

@@ -484,7 +484,7 @@ static void fill_index_wth_head_entries(git_repository *repo, git_index *index)
 	cl_git_pass(git_commit_lookup(&commit, repo, &oid));
 	cl_git_pass(git_commit_tree(&tree, commit));
 
-	cl_git_pass(git_index_read_tree(index, tree));
+	cl_git_pass(git_index_read_tree(index, tree, NULL));
 	cl_git_pass(git_index_write(index));
 
 	git_tree_free(tree);