thodg/libgit2

diff --git a/include/git2.h b/include/git2.h
index 5f6104e..e182ce9 100644
--- a/include/git2.h
+++ b/include/git2.h
@@ -29,6 +29,7 @@
 #include "git2/ignore.h"
 #include "git2/index.h"
 #include "git2/indexer.h"
+#include "git2/mailmap.h"
 #include "git2/merge.h"
 #include "git2/message.h"
 #include "git2/net.h"
diff --git a/include/git2/mailmap.h b/include/git2/mailmap.h
new file mode 100644
index 0000000..bb126d1
--- /dev/null
+++ b/include/git2/mailmap.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_mailmap_h__
+#define INCLUDE_mailmap_h__
+
+#include "common.h"
+#include "repository.h"
+
+/**
+ * @file git2/mailmap.h
+ * @brief Mailmap access subroutines.
+ * @defgroup git_rebase Git merge routines
+ * @ingroup Git
+ * @{
+ */
+GIT_BEGIN_DECL
+
+typedef struct git_mailmap git_mailmap;
+
+struct git_mailmap_entry {
+	const char* name;
+	const char* email;
+};
+
+GIT_EXTERN(int) git_mailmap_create(git_mailmap**, git_repository*);
+GIT_EXTERN(void) git_mailmap_free(git_mailmap*);
+GIT_EXTERN(struct git_mailmap_entry) git_mailmap_lookup(
+	git_mailmap* map,
+	const char* name,
+	const char* email);
+
+/** @} */
+GIT_END_DECL
+
+#endif
diff --git a/src/mailmap.c b/src/mailmap.c
new file mode 100644
index 0000000..26b5f8b
--- /dev/null
+++ b/src/mailmap.c
@@ -0,0 +1,208 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "git2/mailmap.h"
+
+#include "blob.h"
+#include "commit.h"
+#include "git2/common.h"
+#include "git2/repository.h"
+#include "git2/revparse.h"
+#include "git2/sys/commit.h"
+
+struct mailmap_entry {
+	char* to_name;
+	char* to_email;
+	char* from_name;
+	char* from_email;
+};
+
+struct git_mailmap {
+	git_vector lines;
+};
+
+// Returns -1 on failure, length of the string scanned successfully on success,
+// guaranteed to be less that `length`.
+ssize_t parse_name_and_email(
+	const char *line,
+	size_t length,
+	const char** name,
+	size_t* name_len,
+	const char** email,
+	size_t* email_len,
+	bool allow_empty_email)
+{
+	const char* email_start;
+	const char* email_end;
+	const char* name_start;
+	const char* name_end;
+
+	email_start = memchr(line, '<', length);
+	if (!email_start)
+		return -1;
+	email_end = memchr(email_start, '>', length - (email_start - line));
+	if (!email_end)
+		return -1;
+	assert(email_end > email_start);
+
+	*email_len = email_end - email_start - 1;
+	*email = email_start + 1;
+	if (*email == email_end && !allow_empty_email)
+		return -1;
+
+	// Now look for the name.
+	name_start = line;
+	while (name_start < email_start && isspace(*name_start))
+		++name_start;
+
+	*name = name_start;
+
+	name_end = email_start;
+	while (name_end > name_start && isspace(*(name_end - 1)))
+		name_end--;
+
+	assert(name_end >= name_start);
+	*name_len = name_end - name_start;
+
+	return email_end - line;
+}
+
+static void git_mailmap_parse_line(
+	git_mailmap* mailmap,
+	const char* contents,
+	size_t size)
+{
+	struct mailmap_entry* entry;
+
+	const char* to_name;
+	size_t to_name_length;
+
+	const char* to_email;
+	size_t to_email_length;
+
+	const char* from_name;
+	size_t from_name_length;
+
+	const char* from_email;
+	size_t from_email_length;
+
+	ssize_t ret;
+
+	if (!size)
+		return;
+	if (contents[0] == '#')
+		return;
+
+	ret = parse_name_and_email(
+		contents,
+		size,
+		&to_name,
+		&to_name_length,
+		&to_email,
+		&to_email_length,
+		false);
+	if (ret < 0)
+		return;
+
+	ret = parse_name_and_email(
+		contents + ret + 1,
+		size - ret - 1,
+		&from_name,
+		&from_name_length,
+		&from_email,
+		&from_email_length,
+		true);
+	if (ret < 0)
+		return;
+
+	entry = git__malloc(sizeof(struct mailmap_entry));
+
+	entry->to_name = git__strndup(to_name, to_name_length);
+	entry->to_email = git__strndup(to_email, to_email_length);
+	entry->from_name = git__strndup(from_name, from_name_length);
+	entry->from_email = git__strndup(from_email, from_email_length);
+
+	printf("%s <%s> \"%s\" <%s>\n",
+		entry->to_name,
+		entry->to_email,
+		entry->from_name,
+		entry->from_email);
+
+	git_vector_insert(&mailmap->lines, entry);
+}
+
+static void git_mailmap_parse(
+	git_mailmap* mailmap,
+	const char* contents,
+	size_t size)
+{
+	size_t start = 0;
+	size_t i;
+	for (i = 0; i < size; ++i) {
+		if (contents[i] != '\n')
+			continue;
+		git_mailmap_parse_line(mailmap, contents + start, i - start);
+		start = i + 1;
+	}
+}
+
+int git_mailmap_create(git_mailmap** mailmap, git_repository* repo)
+{
+	git_commit* head = NULL;
+	git_blob* mailmap_blob = NULL;
+	git_off_t size = 0;
+	const char* contents = NULL;
+	int ret;
+
+	*mailmap = git__malloc(sizeof(struct git_mailmap));
+	git_vector_init(&(*mailmap)->lines, 0, NULL);
+
+	ret = git_revparse_single((git_object **)&head, repo, "HEAD");
+	if (ret)
+		goto error;
+
+	ret = git_object_lookup_bypath(
+			(git_object**) &mailmap_blob,
+			(const git_object*) head,
+			".mailmap",
+			GIT_OBJ_BLOB);
+	if (ret)
+		goto error;
+
+	contents = git_blob_rawcontent(mailmap_blob);
+	size = git_blob_rawsize(mailmap_blob);
+
+	git_mailmap_parse(*mailmap, contents, size);
+
+	return 0;
+
+error:
+	assert(ret);
+
+	if (mailmap_blob)
+		git_blob_free(mailmap_blob);
+	if (head)
+		git_commit_free(head);
+	git_mailmap_free(*mailmap);
+	return ret;
+}
+
+void git_mailmap_free(struct git_mailmap* mailmap)
+{
+	size_t i;
+	struct mailmap_entry* line;
+	git_vector_foreach(&mailmap->lines, i, line) {
+		git__free((char*)line->to_name);
+		git__free((char*)line->to_email);
+		git__free((char*)line->from_name);
+		git__free((char*)line->from_email);
+		git__free(line);
+	}
+
+	git_vector_clear(&mailmap->lines);
+	git__free(mailmap);
+}