1 files changed, 164 insertions, 181 deletions

diff --git a/src/index.c b/src/index.c
index 66e7a81da..f1ae9a710 100644
--- a/src/index.c
+++ b/src/index.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009-2011 the libgit2 contributors
+ * Copyright (C) 2009-2012 the libgit2 contributors
  *
  * This file is part of libgit2, distributed under the GNU GPL v2 with
  * a Linking Exception. For full terms see the included COPYING file.
@@ -135,22 +135,17 @@ int git_index_open(git_index **index_out, const char *index_path)
 
 	assert(index_out && index_path);
 
-	index = git__malloc(sizeof(git_index));
-	if (index == NULL)
-		return GIT_ENOMEM;
-
-	memset(index, 0x0, sizeof(git_index));
+	index = git__calloc(1, sizeof(git_index));
+	GITERR_CHECK_ALLOC(index);
 
 	index->index_file_path = git__strdup(index_path);
-	if (index->index_file_path == NULL) {
-		git__free(index);
-		return GIT_ENOMEM;
-	}
+	GITERR_CHECK_ALLOC(index->index_file_path);
 
-	git_vector_init(&index->entries, 32, index_cmp);
+	if (git_vector_init(&index->entries, 32, index_cmp) < 0)
+		return -1;
 
 	/* Check if index file is stored on disk already */
-	if (git_path_exists(index->index_file_path) == 0)
+	if (git_path_exists(index->index_file_path) == true)
 		index->on_disk = 1;
 
 	*index_out = index;
@@ -215,36 +210,35 @@ void git_index_clear(git_index *index)
 
 int git_index_read(git_index *index)
 {
-	int error = GIT_SUCCESS, updated;
-	git_fbuffer buffer = GIT_FBUFFER_INIT;
+	int error, updated;
+	git_buf buffer = GIT_BUF_INIT;
 	time_t mtime;
 
 	assert(index->index_file_path);
 
-	if (!index->on_disk || git_path_exists(index->index_file_path) < 0) {
+	if (!index->on_disk || git_path_exists(index->index_file_path) == false) {
 		git_index_clear(index);
 		index->on_disk = 0;
-		return GIT_SUCCESS;
+		return 0;
 	}
 
 	/* We don't want to update the mtime if we fail to parse the index */
 	mtime = index->last_modified;
-	error = git_futils_readbuffer_updated(&buffer, index->index_file_path, &mtime, &updated);
-	if (error < GIT_SUCCESS)
-		return git__rethrow(error, "Failed to read index");
+	error = git_futils_readbuffer_updated(
+		&buffer, index->index_file_path, &mtime, &updated);
+	if (error < 0)
+		return error;
 
 	if (updated) {
 		git_index_clear(index);
-		error = parse_index(index, buffer.data, buffer.len);
+		error = parse_index(index, buffer.ptr, buffer.size);
 
-		if (error == GIT_SUCCESS)
+		if (!error)
 			index->last_modified = mtime;
 
-		git_futils_freebuffer(&buffer);
+		git_buf_free(&buffer);
 	}
 
-	if (error < GIT_SUCCESS)
-		return git__rethrow(error, "Failed to parse index");
 	return error;
 }
 
@@ -256,23 +250,24 @@ int git_index_write(git_index *index)
 
 	git_vector_sort(&index->entries);
 
-	if ((error = git_filebuf_open(&file, index->index_file_path, GIT_FILEBUF_HASH_CONTENTS)) < GIT_SUCCESS)
-		return git__rethrow(error, "Failed to write index");
+	if ((error = git_filebuf_open(
+			 &file, index->index_file_path, GIT_FILEBUF_HASH_CONTENTS)) < 0)
+		return error;
 
-	if ((error = write_index(index, &file)) < GIT_SUCCESS) {
+	if ((error = write_index(index, &file)) < 0) {
 		git_filebuf_cleanup(&file);
-		return git__rethrow(error, "Failed to write index");
+		return error;
 	}
 
-	if ((error = git_filebuf_commit(&file, GIT_INDEX_FILE_MODE)) < GIT_SUCCESS)
-		return git__rethrow(error, "Failed to write index");
+	if ((error = git_filebuf_commit(&file, GIT_INDEX_FILE_MODE)) < 0)
+		return error;
 
 	if (p_stat(index->index_file_path, &indexst) == 0) {
 		index->last_modified = indexst.st_mtime;
 		index->on_disk = 1;
 	}
 
-	return GIT_SUCCESS;
+	return 0;
 }
 
 unsigned int git_index_entrycount(git_index *index)
@@ -293,6 +288,20 @@ git_index_entry *git_index_get(git_index *index, unsigned int n)
 	return git_vector_get(&index->entries, n);
 }
 
+void git_index__init_entry_from_stat(struct stat *st, git_index_entry *entry)
+{
+	entry->ctime.seconds = (git_time_t)st->st_ctime;
+	entry->mtime.seconds = (git_time_t)st->st_mtime;
+	/* entry->mtime.nanoseconds = st->st_mtimensec; */
+	/* entry->ctime.nanoseconds = st->st_ctimensec; */
+	entry->dev  = st->st_rdev;
+	entry->ino  = st->st_ino;
+	entry->mode = index_create_mode(st->st_mode);
+	entry->uid  = st->st_uid;
+	entry->gid  = st->st_gid;
+	entry->file_size = st->st_size;
+}
+
 static int index_entry_init(git_index_entry **entry_out, git_index *index, const char *rel_path, int stage)
 {
 	git_index_entry *entry = NULL;
@@ -302,25 +311,20 @@ static int index_entry_init(git_index_entry **entry_out, git_index *index, const
 	git_buf full_path = GIT_BUF_INIT;
 	int error;
 
-	if (INDEX_OWNER(index) == NULL)
-		return git__throw(GIT_EBAREINDEX,
-			"Failed to initialize entry. Repository is bare");
+	assert(stage >= 0 && stage <= 3);
 
-	if (stage < 0 || stage > 3)
-		return git__throw(GIT_ERROR,
-			"Failed to initialize entry. Invalid stage %i", stage);
-
-	workdir = git_repository_workdir(INDEX_OWNER(index));
-	if (workdir == NULL)
-		return git__throw(GIT_EBAREINDEX,
-			"Failed to initialize entry. Cannot resolved workdir");
+	if (INDEX_OWNER(index) == NULL ||
+		(workdir = git_repository_workdir(INDEX_OWNER(index))) == NULL)
+	{
+		giterr_set(GITERR_INDEX,
+			"Could not initialize index entry. Repository is bare");
+		return -1;
+	}
 
-	error = git_buf_joinpath(&full_path, workdir, rel_path);
-	if (error < GIT_SUCCESS)
+	if ((error = git_buf_joinpath(&full_path, workdir, rel_path)) < 0)
 		return error;
 
-	if (p_lstat(full_path.ptr, &st) < 0) {
-		error = git__throw(GIT_ENOTFOUND, "Failed to initialize entry. '%s' cannot be opened. %s", full_path.ptr, strerror(errno));
+	if ((error = git_path_lstat(full_path.ptr, &st)) < 0) {
 		git_buf_free(&full_path);
 		return error;
 	}
@@ -332,34 +336,21 @@ static int index_entry_init(git_index_entry **entry_out, git_index *index, const
 	 */
 
 	/* write the blob to disk and get the oid */
-	if ((error = git_blob_create_fromfile(&oid, INDEX_OWNER(index), rel_path)) < GIT_SUCCESS)
-		return git__rethrow(error, "Failed to initialize index entry");
+	if ((error = git_blob_create_fromfile(&oid, INDEX_OWNER(index), rel_path)) < 0)
+		return error;
 
 	entry = git__calloc(1, sizeof(git_index_entry));
-	if (!entry)
-		return GIT_ENOMEM;
-
-	entry->ctime.seconds = (git_time_t)st.st_ctime;
-	entry->mtime.seconds = (git_time_t)st.st_mtime;
-	/* entry.mtime.nanoseconds = st.st_mtimensec; */
-	/* entry.ctime.nanoseconds = st.st_ctimensec; */
-	entry->dev= st.st_rdev;
-	entry->ino = st.st_ino;
-	entry->mode = index_create_mode(st.st_mode);
-	entry->uid = st.st_uid;
-	entry->gid = st.st_gid;
-	entry->file_size = st.st_size;
-	entry->oid = oid;
+	GITERR_CHECK_ALLOC(entry);
 
+	git_index__init_entry_from_stat(&st, entry);
+
+	entry->oid = oid;
 	entry->flags |= (stage << GIT_IDXENTRY_STAGESHIFT);
 	entry->path = git__strdup(rel_path);
-	if (entry->path == NULL) {
-		git__free(entry);
-		return GIT_ENOMEM;
-	}
+	GITERR_CHECK_ALLOC(entry->path);
 
 	*entry_out = entry;
-	return GIT_SUCCESS;
+	return 0;
 }
 
 static git_index_entry *index_entry_dup(const git_index_entry *source_entry)
@@ -394,10 +385,7 @@ static int index_insert(git_index *index, git_index_entry *entry, int replace)
 	int position;
 	git_index_entry **entry_array;
 
-	assert(index && entry);
-
-	if (entry->path == NULL)
-		return git__throw(GIT_EMISSINGOBJDATA, "Failed to insert into index. Entry has no path");
+	assert(index && entry && entry->path != NULL);
 
 	/* make sure that the path length flag is correct */
 	path_length = strlen(entry->path);
@@ -413,12 +401,8 @@ static int index_insert(git_index *index, git_index_entry *entry, int replace)
 	 * replacing is not requested: just insert entry at the end;
 	 * the index is no longer sorted
 	 */
-	if (!replace) {
-		if (git_vector_insert(&index->entries, entry) < GIT_SUCCESS)
-			return GIT_ENOMEM;
-
-		return GIT_SUCCESS;
-	}
+	if (!replace)
+		return git_vector_insert(&index->entries, entry);
 
 	/* look if an entry with this path already exists */
 	position = git_index_find(index, entry->path);
@@ -427,12 +411,8 @@ static int index_insert(git_index *index, git_index_entry *entry, int replace)
 	 * if no entry exists add the entry at the end;
 	 * the index is no longer sorted
 	 */
-	if (position == GIT_ENOTFOUND) {
-		if (git_vector_insert(&index->entries, entry) < GIT_SUCCESS)
-			return GIT_ENOMEM;
-
-		return GIT_SUCCESS;
-	}
+	if (position == GIT_ENOTFOUND)
+		return git_vector_insert(&index->entries, entry);
 
 	/* exists, replace it */
 	entry_array = (git_index_entry **) index->entries.contents;
@@ -440,7 +420,7 @@ static int index_insert(git_index *index, git_index_entry *entry, int replace)
 	git__free(entry_array[position]);
 	entry_array[position] = entry;
 
-	return GIT_SUCCESS;
+	return 0;
 }
 
 static int index_add(git_index *index, const char *path, int stage, int replace)
@@ -448,20 +428,15 @@ static int index_add(git_index *index, const char *path, int stage, int replace)
 	git_index_entry *entry = NULL;
 	int ret;
 
-	ret = index_entry_init(&entry, index, path, stage);
-	if (ret)
-		goto err;
-
-	ret = index_insert(index, entry, replace);
-	if (ret)
-		goto err;
+	if ((ret = index_entry_init(&entry, index, path, stage)) < 0 ||
+		(ret = index_insert(index, entry, replace)) < 0)
+	{
+		index_entry_free(entry);
+		return ret;
+	}
 
 	git_tree_cache_invalidate_path(index->tree, entry->path);
-
-	return ret;
-err:
-	index_entry_free(entry);
-	return git__rethrow(ret, "Failed to append to index");
+	return 0;
 }
 
 int git_index_add(git_index *index, const char *path, int stage)
@@ -474,28 +449,23 @@ int git_index_append(git_index *index, const char *path, int stage)
 	return index_add(index, path, stage, 0);
 }
 
-static int index_add2(git_index *index, const git_index_entry *source_entry,
-		int replace)
+static int index_add2(
+	git_index *index, const git_index_entry *source_entry, int replace)
 {
 	git_index_entry *entry = NULL;
 	int ret;
 
 	entry = index_entry_dup(source_entry);
-	if (entry == NULL) {
-		ret = GIT_ENOMEM;
-		goto err;
-	}
+	if (entry == NULL)
+		return -1;
 
-	ret = index_insert(index, entry, replace);
-	if (ret)
-		goto err;
+	if ((ret = index_insert(index, entry, replace)) < 0) {
+		index_entry_free(entry);
+		return ret;
+	}
 
 	git_tree_cache_invalidate_path(index->tree, entry->path);
-
-	return ret;
-err:
-	index_entry_free(entry);
-	return git__rethrow(ret, "Failed to append to index");
+	return 0;
 }
 
 int git_index_add2(git_index *index, const git_index_entry *source_entry)
@@ -514,13 +484,14 @@ int git_index_remove(git_index *index, int position)
 	git_index_entry *entry;
 
 	git_vector_sort(&index->entries);
+
 	entry = git_vector_get(&index->entries, position);
 	if (entry != NULL)
 		git_tree_cache_invalidate_path(index->tree, entry->path);
 
 	error = git_vector_remove(&index->entries, (unsigned int)position);
 
-	if (error == GIT_SUCCESS)
+	if (!error)
 		index_entry_free(entry);
 
 	return error;
@@ -531,12 +502,22 @@ int git_index_find(git_index *index, const char *path)
 	return git_vector_bsearch2(&index->entries, index_srch, path);
 }
 
+unsigned int git_index__prefix_position(git_index *index, const char *path)
+{
+	unsigned int pos;
+
+	git_vector_bsearch3(&pos, &index->entries, index_srch, path);
+
+	return pos;
+}
+
 void git_index_uniq(git_index *index)
 {
 	git_vector_uniq(&index->entries);
 }
 
-const git_index_entry_unmerged *git_index_get_unmerged_bypath(git_index *index, const char *path)
+const git_index_entry_unmerged *git_index_get_unmerged_bypath(
+	git_index *index, const char *path)
 {
 	int pos;
 	assert(index && path);
@@ -544,75 +525,87 @@ const git_index_entry_unmerged *git_index_get_unmerged_bypath(git_index *index,
 	if (!index->unmerged.length)
 		return NULL;
 
-	if ((pos = git_vector_bsearch2(&index->unmerged, unmerged_srch, path)) < GIT_SUCCESS)
+	if ((pos = git_vector_bsearch2(&index->unmerged, unmerged_srch, path)) < 0)
 		return NULL;
 
 	return git_vector_get(&index->unmerged, pos);
 }
 
-const git_index_entry_unmerged *git_index_get_unmerged_byindex(git_index *index, unsigned int n)
+const git_index_entry_unmerged *git_index_get_unmerged_byindex(
+	git_index *index, unsigned int n)
 {
 	assert(index);
 	return git_vector_get(&index->unmerged, n);
 }
 
+static int index_error_invalid(const char *message)
+{
+	giterr_set(GITERR_INDEX, "Invalid data in index - %s", message);
+	return -1;
+}
+
 static int read_unmerged(git_index *index, const char *buffer, size_t size)
 {
 	const char *endptr;
 	size_t len;
 	int i;
 
-	git_vector_init(&index->unmerged, 16, unmerged_cmp);
+	if (git_vector_init(&index->unmerged, 16, unmerged_cmp) < 0)
+		return -1;
 
 	while (size) {
 		git_index_entry_unmerged *lost;
 
 		len = strlen(buffer) + 1;
 		if (size <= len)
-			return git__throw(GIT_ERROR, "Failed to read unmerged entries");
+			return index_error_invalid("reading unmerged entries");
 
-		if ((lost = git__malloc(sizeof(git_index_entry_unmerged))) == NULL)
-			return GIT_ENOMEM;
+		lost = git__malloc(sizeof(git_index_entry_unmerged));
+		GITERR_CHECK_ALLOC(lost);
 
-		if (git_vector_insert(&index->unmerged, lost) < GIT_SUCCESS)
-			return git__throw(GIT_ERROR, "Failed to read unmerged entries");
+		if (git_vector_insert(&index->unmerged, lost) < 0)
+			return -1;
 
+		/* read NUL-terminated pathname for entry */
 		lost->path = git__strdup(buffer);
-		if (!lost->path)
-			return GIT_ENOMEM;
+		GITERR_CHECK_ALLOC(lost->path);
 
 		size -= len;
 		buffer += len;
 
+		/* read 3 ASCII octal numbers for stage entries */
 		for (i = 0; i < 3; i++) {
 			int tmp;
 
-			if (git__strtol32(&tmp, buffer, &endptr, 8) < GIT_SUCCESS ||
-				!endptr || endptr == buffer || *endptr || (unsigned)tmp > UINT_MAX)
-				return GIT_ERROR;
+			if (git__strtol32(&tmp, buffer, &endptr, 8) < 0 ||
+				!endptr || endptr == buffer || *endptr ||
+				(unsigned)tmp > UINT_MAX)
+				return index_error_invalid("reading unmerged entry stage");
 
 			lost->mode[i] = tmp;
 
 			len = (endptr + 1) - buffer;
 			if (size <= len)
-				return git__throw(GIT_ERROR, "Failed to read unmerged entries");
+				return index_error_invalid("reading unmerged entry stage");
 
 			size -= len;
 			buffer += len;
 		}
 
+		/* read up to 3 OIDs for stage entries */
 		for (i = 0; i < 3; i++) {
 			if (!lost->mode[i])
 				continue;
 			if (size < 20)
-				return git__throw(GIT_ERROR, "Failed to read unmerged entries");
+				return index_error_invalid("reading unmerged entry oid");
+
 			git_oid_fromraw(&lost->oid[i], (const unsigned char *) buffer);
 			size -= 20;
 			buffer += 20;
 		}
 	}
 
-	return GIT_SUCCESS;
+	return 0;
 }
 
 static size_t read_entry(git_index_entry *dest, const void *buffer, size_t buffer_size)
@@ -658,7 +651,7 @@ static size_t read_entry(git_index_entry *dest, const void *buffer, size_t buffe
 
 		path_end = memchr(path_ptr, '\0', buffer_size);
 		if (path_end == NULL)
-				return 0;
+			return 0;
 
 		path_length = path_end - path_ptr;
 	}
@@ -683,15 +676,15 @@ static int read_header(struct index_header *dest, const void *buffer)
 
 	dest->signature = ntohl(source->signature);
 	if (dest->signature != INDEX_HEADER_SIG)
-		return GIT_EOBJCORRUPTED;
+		return index_error_invalid("incorrect header signature");
 
 	dest->version = ntohl(source->version);
 	if (dest->version != INDEX_VERSION_NUMBER_EXT &&
 		dest->version != INDEX_VERSION_NUMBER)
-		return GIT_EOBJCORRUPTED;
+		return index_error_invalid("incorrect header version");
 
 	dest->entry_count = ntohl(source->entry_count);
-	return GIT_SUCCESS;
+	return 0;
 }
 
 static size_t read_extension(git_index *index, const char *buffer, size_t buffer_size)
@@ -714,10 +707,10 @@ static size_t read_extension(git_index *index, const char *buffer, size_t buffer
 	if (dest.signature[0] >= 'A' && dest.signature[0] <= 'Z') {
 		/* tree cache */
 		if (memcmp(dest.signature, INDEX_EXT_TREECACHE_SIG, 4) == 0) {
-			if (git_tree_cache_read(&index->tree, buffer + 8, dest.extension_size) < GIT_SUCCESS)
+			if (git_tree_cache_read(&index->tree, buffer + 8, dest.extension_size) < 0)
 				return 0;
 		} else if (memcmp(dest.signature, INDEX_EXT_UNMERGED_SIG, 4) == 0) {
-			if (read_unmerged(index, buffer + 8, dest.extension_size) < GIT_SUCCESS)
+			if (read_unmerged(index, buffer + 8, dest.extension_size) < 0)
 				return 0;
 		}
 		/* else, unsupported extension. We cannot parse this, but we can skip
@@ -739,21 +732,21 @@ static int parse_index(git_index *index, const char *buffer, size_t buffer_size)
 
 #define seek_forward(_increase) { \
 	if (_increase >= buffer_size) \
-		return git__throw(GIT_EOBJCORRUPTED, "Failed to seek forward. Buffer size exceeded"); \
+		return index_error_invalid("ran out of data while parsing"); \
 	buffer += _increase; \
 	buffer_size -= _increase;\
 }
 
 	if (buffer_size < INDEX_HEADER_SIZE + INDEX_FOOTER_SIZE)
-		return git__throw(GIT_EOBJCORRUPTED, "Failed to parse index. Buffer too small");
+		return index_error_invalid("insufficient buffer space");
 
 	/* Precalculate the SHA1 of the files's contents -- we'll match it to
 	 * the provided SHA1 in the footer */
 	git_hash_buf(&checksum_calculated, buffer, buffer_size - INDEX_FOOTER_SIZE);
 
 	/* Parse header */
-	if (read_header(&header, buffer) < GIT_SUCCESS)
-		return git__throw(GIT_EOBJCORRUPTED, "Failed to parse index. Header is corrupted");
+	if (read_header(&header, buffer) < 0)
+		return -1;
 
 	seek_forward(INDEX_HEADER_SIZE);
 
@@ -765,23 +758,22 @@ static int parse_index(git_index *index, const char *buffer, size_t buffer_size)
 		git_index_entry *entry;
 
 		entry = git__malloc(sizeof(git_index_entry));
-		if (entry == NULL)
-			return GIT_ENOMEM;
+		GITERR_CHECK_ALLOC(entry);
 
 		entry_size = read_entry(entry, buffer, buffer_size);
 
 		/* 0 bytes read means an object corruption */
 		if (entry_size == 0)
-			return git__throw(GIT_EOBJCORRUPTED, "Failed to parse index. Entry size is zero");
+			return index_error_invalid("invalid entry");
 
-		if (git_vector_insert(&index->entries, entry) < GIT_SUCCESS)
-			return GIT_ENOMEM;
+		if (git_vector_insert(&index->entries, entry) < 0)
+			return -1;
 
 		seek_forward(entry_size);
 	}
 
 	if (i != header.entry_count)
-		return git__throw(GIT_EOBJCORRUPTED, "Failed to parse index. Header entries changed while parsing");
+		return index_error_invalid("header entries changed while parsing");
 
 	/* There's still space for some extensions! */
 	while (buffer_size > INDEX_FOOTER_SIZE) {
@@ -791,43 +783,43 @@ static int parse_index(git_index *index, const char *buffer, size_t buffer_size)
 
 		/* see if we have read any bytes from the extension */
 		if (extension_size == 0)
-			return git__throw(GIT_EOBJCORRUPTED, "Failed to parse index. Extension size is zero");
+			return index_error_invalid("extension size is zero");
 
 		seek_forward(extension_size);
 	}
 
 	if (buffer_size != INDEX_FOOTER_SIZE)
-		return git__throw(GIT_EOBJCORRUPTED, "Failed to parse index. Buffer size does not match index footer size");
+		return index_error_invalid("buffer size does not match index footer size");
 
 	/* 160-bit SHA-1 over the content of the index file before this checksum. */
 	git_oid_fromraw(&checksum_expected, (const unsigned char *)buffer);
 
 	if (git_oid_cmp(&checksum_calculated, &checksum_expected) != 0)
-		return git__throw(GIT_EOBJCORRUPTED, "Failed to parse index. Calculated checksum does not match expected checksum");
+		return index_error_invalid("calculated checksum does not match expected");
 
 #undef seek_forward
 
 	/* force sorting in the vector: the entries are
 	 * assured to be sorted on the index */
 	index->entries.sorted = 1;
-	return GIT_SUCCESS;
+	return 0;
 }
 
 static int is_index_extended(git_index *index)
 {
 	unsigned int i, extended;
+	git_index_entry *entry;
 
 	extended = 0;
 
-	for (i = 0; i < index->entries.length; ++i) {
-		git_index_entry *entry;
-		entry = git_vector_get(&index->entries, i);
+	git_vector_foreach(&index->entries, i, entry) {
 		entry->flags &= ~GIT_IDXENTRY_EXTENDED;
 		if (entry->flags_extended & GIT_IDXENTRY_EXTENDED_FLAGS) {
 			extended++;
 			entry->flags |= GIT_IDXENTRY_EXTENDED;
 		}
 	}
+
 	return extended;
 }
 
@@ -845,8 +837,8 @@ static int write_disk_entry(git_filebuf *file, git_index_entry *entry)
 	else
 		disk_size = short_entry_size(path_len);
 
-	if (git_filebuf_reserve(file, &mem, disk_size) < GIT_SUCCESS)
-		return GIT_ENOMEM;
+	if (git_filebuf_reserve(file, &mem, disk_size) < 0)
+		return -1;
 
 	ondisk = (struct entry_short *)mem;
 
@@ -888,7 +880,7 @@ static int write_disk_entry(git_filebuf *file, git_index_entry *entry)
 
 	memcpy(path, entry->path, path_len);
 
-	return GIT_SUCCESS;
+	return 0;
 }
 
 static int write_entries(git_index *index, git_filebuf *file)
@@ -898,16 +890,15 @@ static int write_entries(git_index *index, git_filebuf *file)
 	for (i = 0; i < index->entries.length; ++i) {
 		git_index_entry *entry;
 		entry = git_vector_get(&index->entries, i);
-		if (write_disk_entry(file, entry) < GIT_SUCCESS)
-			return GIT_ENOMEM;
+		if (write_disk_entry(file, entry) < 0)
+			return -1;
 	}
 
-	return GIT_SUCCESS;
+	return 0;
 }
 
 static int write_index(git_index *index, git_filebuf *file)
 {
-	int error = GIT_SUCCESS;
 	git_oid hash_final;
 
 	struct index_header header;
@@ -922,11 +913,11 @@ static int write_index(git_index *index, git_filebuf *file)
 	header.version = htonl(is_extended ? INDEX_VERSION_NUMBER_EXT : INDEX_VERSION_NUMBER);
 	header.entry_count = htonl(index->entries.length);
 
-	git_filebuf_write(file, &header, sizeof(struct index_header));
+	if (git_filebuf_write(file, &header, sizeof(struct index_header)) < 0)
+		return -1;
 
-	error = write_entries(index, file);
-	if (error < GIT_SUCCESS)
-		return git__rethrow(error, "Failed to write index");
+	if (write_entries(index, file) < 0)
+		return -1;
 
 	/* TODO: write extensions (tree cache) */
 
@@ -934,9 +925,7 @@ static int write_index(git_index *index, git_filebuf *file)
 	git_filebuf_hash(&hash_final, file);
 
 	/* write it at the end of the file */
-	git_filebuf_write(file, hash_final.id, GIT_OID_RAWSZ);
-
-	return error == GIT_SUCCESS ? GIT_SUCCESS : git__rethrow(error, "Failed to write index");
+	return git_filebuf_write(file, hash_final.id, GIT_OID_RAWSZ);
 }
 
 int git_index_entry_stage(const git_index_entry *entry)
@@ -946,36 +935,30 @@ int git_index_entry_stage(const git_index_entry *entry)
 
 static int read_tree_cb(const char *root, git_tree_entry *tentry, void *data)
 {
-	int ret = GIT_SUCCESS;
 	git_index *index = data;
 	git_index_entry *entry = NULL;
 	git_buf path = GIT_BUF_INIT;
 
-	if (entry_is_tree(tentry))
-		goto exit;
+	if (git_tree_entry__is_tree(tentry))
+		return 0;
 
-	ret = git_buf_joinpath(&path, root, tentry->filename);
-	if (ret < GIT_SUCCESS)
-		goto exit;
+	if (git_buf_joinpath(&path, root, tentry->filename) < 0)
+		return -1;
 
 	entry = git__calloc(1, sizeof(git_index_entry));
-	if (!entry) {
-		ret = GIT_ENOMEM;
-		goto exit;
-	}
+	GITERR_CHECK_ALLOC(entry);
 
 	entry->mode = tentry->attr;
 	entry->oid = tentry->oid;
 	entry->path = git_buf_detach(&path);
-
-	ret = index_insert(index, entry, 0);
-
-exit:
 	git_buf_free(&path);
 
-	if (ret < GIT_SUCCESS)
+	if (index_insert(index, entry, 0) < 0) {
 		index_entry_free(entry);
-	return ret;
+		return -1;
+	}
+
+	return 0;
 }
 
 int git_index_read_tree(git_index *index, git_tree *tree)