Ported t04_commit.c to Clar.

Created a copy of tests/resources/testrepo.git that is compatible
with the Clar sandboxing helpers.

Restructured commit test suites to use Clar sandbox helpers.

Now using typed data arrays rather than lots of macros to define test
cases.

CMakeLists.txt

@@ -147,11 +147,14 @@ IF (BUILD_TESTS)
 ENDIF ()
 
 IF (BUILD_CLAR)
+
 	FIND_PACKAGE(PythonInterp REQUIRED)
 
 	SET(CLAR_FIXTURES "${CMAKE_CURRENT_SOURCE_DIR}/tests/resources/")
 	SET(CLAR_PATH "${CMAKE_CURRENT_SOURCE_DIR}/tests-clar")
+	SET(CLAR_RESOURCES "${CMAKE_CURRENT_SOURCE_DIR}/tests-clar/resources" CACHE PATH "Path to test resources.")
 	ADD_DEFINITIONS(-DCLAR_FIXTURE_PATH=\"${CLAR_FIXTURES}\")
+	ADD_DEFINITIONS(-DCLAR_RESOURCES=\"${TEST_RESOURCES}\")
 
 	INCLUDE_DIRECTORIES(${CLAR_PATH})
 	FILE(GLOB_RECURSE SRC_TEST ${CLAR_PATH}/*/*.c ${CLAR_PATH}/clar_helpers.c ${CLAR_PATH}/testlib.c)

tests-clar/commit/parse.c

@@ -0,0 +1,350 @@
+#include "clar_libgit2.h"
+#include <git2/types.h>
+#include "commit.h"
+#include "signature.h"
+
+// Fixture setup
+static git_repository *g_repo;
+void test_commit_parse__initialize(void)
+{
+   g_repo = cl_git_sandbox_init("testrepo");
+}
+void test_commit_parse__cleanup(void)
+{
+   cl_git_sandbox_cleanup();
+}
+
+
+// Header parsing
+typedef struct {
+   const char *line;
+   const char *header;
+} parse_test_case;
+
+static parse_test_case passing_header_cases[] = {
+   { "parent 05452d6349abcd67aa396dfb28660d765d8b2a36\n", "parent " },
+   { "tree 05452d6349abcd67aa396dfb28660d765d8b2a36\n", "tree " },
+   { "random_heading 05452d6349abcd67aa396dfb28660d765d8b2a36\n", "random_heading " },
+   { "stuck_heading05452d6349abcd67aa396dfb28660d765d8b2a36\n", "stuck_heading" },
+   { "tree 5F4BEFFC0759261D015AA63A3A85613FF2F235DE\n", "tree " },
+   { "tree 1A669B8AB81B5EB7D9DB69562D34952A38A9B504\n", "tree " },
+   { "tree 5B20DCC6110FCC75D31C6CEDEBD7F43ECA65B503\n", "tree " },
+   { "tree 173E7BF00EA5C33447E99E6C1255954A13026BE4\n", "tree " },
+   { NULL, NULL }
+};
+
+static parse_test_case failing_header_cases[] = {
+   { "parent 05452d6349abcd67aa396dfb28660d765d8b2a36", "parent " },
+   { "05452d6349abcd67aa396dfb28660d765d8b2a36\n", "tree " },
+   { "parent05452d6349abcd67aa396dfb28660d765d8b2a6a\n", "parent " },
+   { "parent 05452d6349abcd67aa396dfb280d765d8b2a6\n", "parent " },
+   { "tree  05452d6349abcd67aa396dfb28660d765d8b2a36\n", "tree " },
+   { "parent 0545xd6349abcd67aa396dfb28660d765d8b2a36\n", "parent " },
+   { "parent 0545xd6349abcd67aa396dfb28660d765d8b2a36FF\n", "parent " },
+   { "", "tree " },
+   { "", "" },
+   { NULL, NULL }
+};
+
+void test_commit_parse__header(void)
+{
+   git_oid oid;
+
+   parse_test_case *testcase;
+   for (testcase = passing_header_cases; testcase->line != NULL; testcase++)
+   {
+      const char *line = testcase->line;
+      const char *line_end = line + strlen(line);
+
+      cl_git_pass(git_oid__parse(&oid, &line, line_end, testcase->header));
+      cl_assert(line == line_end);
+   }
+
+   for (testcase = failing_header_cases; testcase->line != NULL; testcase++)
+   {
+      const char *line = testcase->line;
+      const char *line_end = line + strlen(line);
+
+      cl_git_fail(git_oid__parse(&oid, &line, line_end, testcase->header));
+   }
+}
+
+
+// Signature parsing
+typedef struct {
+   const char *string;
+   const char *header;
+   const char *name;
+   const char *email;
+   git_time_t time;
+   int offset;
+} passing_signature_test_case;
+
+passing_signature_test_case passing_signature_cases[] = {
+	{"author Vicent Marti <tanoku@gmail.com> 12345 \n", "author ", "Vicent Marti", "tanoku@gmail.com", 12345, 0},
+	{"author Vicent Marti <> 12345 \n", "author ", "Vicent Marti", "", 12345, 0},
+	{"author Vicent Marti <tanoku@gmail.com> 231301 +1020\n", "author ", "Vicent Marti", "tanoku@gmail.com", 231301, 620},
+	{"author Vicent Marti with an outrageously long name which will probably overflow the buffer <tanoku@gmail.com> 12345 \n", "author ", "Vicent Marti with an outrageously long name which will probably overflow the buffer", "tanoku@gmail.com", 12345, 0},
+	{"author Vicent Marti <tanokuwithaveryveryverylongemailwhichwillprobablyvoverflowtheemailbuffer@gmail.com> 12345 \n", "author ", "Vicent Marti", "tanokuwithaveryveryverylongemailwhichwillprobablyvoverflowtheemailbuffer@gmail.com", 12345, 0},
+	{"committer Vicent Marti <tanoku@gmail.com> 123456 +0000 \n", "committer ", "Vicent Marti", "tanoku@gmail.com", 123456, 0},
+	{"committer Vicent Marti <tanoku@gmail.com> 123456 +0100 \n", "committer ", "Vicent Marti", "tanoku@gmail.com", 123456, 60},
+	{"committer Vicent Marti <tanoku@gmail.com> 123456 -0100 \n", "committer ", "Vicent Marti", "tanoku@gmail.com", 123456, -60},
+	// Parse a signature without an author field
+	{"committer <tanoku@gmail.com> 123456 -0100 \n", "committer ", "", "tanoku@gmail.com", 123456, -60},
+	// Parse a signature without an author field
+	{"committer  <tanoku@gmail.com> 123456 -0100 \n", "committer ", "", "tanoku@gmail.com", 123456, -60},
+	// Parse a signature with an empty author field
+	{"committer   <tanoku@gmail.com> 123456 -0100 \n", "committer ", "", "tanoku@gmail.com", 123456, -60},
+	// Parse a signature with an empty email field
+	{"committer Vicent Marti <> 123456 -0100 \n", "committer ", "Vicent Marti", "", 123456, -60},
+	// Parse a signature with an empty email field
+	{"committer Vicent Marti < > 123456 -0100 \n", "committer ", "Vicent Marti", "", 123456, -60},
+	// Parse a signature with empty name and email
+	{"committer <> 123456 -0100 \n", "committer ", "", "", 123456, -60},
+	// Parse a signature with empty name and email
+	{"committer  <> 123456 -0100 \n", "committer ", "", "", 123456, -60},
+	// Parse a signature with empty name and email
+	{"committer  < > 123456 -0100 \n", "committer ", "", "", 123456, -60},
+	// Parse an obviously invalid signature
+	{"committer foo<@bar> 123456 -0100 \n", "committer ", "foo", "@bar", 123456, -60},
+	// Parse an obviously invalid signature
+	{"committer    foo<@bar>123456 -0100 \n", "committer ", "foo", "@bar", 123456, -60},
+	// Parse an obviously invalid signature
+	{"committer <>\n", "committer ", "", "", 0, 0},
+	{"committer Vicent Marti <tanoku@gmail.com> 123456 -1500 \n", "committer ", "Vicent Marti", "tanoku@gmail.com", 0, 0},
+	{"committer Vicent Marti <tanoku@gmail.com> 123456 +0163 \n", "committer ", "Vicent Marti", "tanoku@gmail.com", 0, 0},
+	{"author Vicent Marti <tanoku@gmail.com> notime \n", "author ", "Vicent Marti", "tanoku@gmail.com", 0, 0},
+	{"author Vicent Marti <tanoku@gmail.com> 123456 notimezone \n", "author ", "Vicent Marti", "tanoku@gmail.com", 0, 0},
+	{"author Vicent Marti <tanoku@gmail.com> notime +0100\n", "author ", "Vicent Marti", "tanoku@gmail.com", 0, 0},
+	{"author Vicent Marti <tanoku@gmail.com>\n", "author ", "Vicent Marti", "tanoku@gmail.com", 0, 0},
+	{"author A U Thor <author@example.com>,  C O. Miter <comiter@example.com> 1234567890 -0700\n", "author ", "A U Thor", "author@example.com", 1234567890, -420},
+	{"author A U Thor <author@example.com> and others 1234567890 -0700\n", "author ", "A U Thor", "author@example.com", 1234567890, -420},
+	{"author A U Thor <author@example.com> and others 1234567890\n", "author ", "A U Thor", "author@example.com", 1234567890, 0},
+	{"author A U Thor> <author@example.com> and others 1234567890\n", "author ", "A U Thor>", "author@example.com", 1234567890, 0},
+   {NULL,NULL,NULL,NULL,0,0}
+};
+
+typedef struct {
+   const char *string;
+   const char *header;
+} failing_signature_test_case;
+
+failing_signature_test_case failing_signature_cases[] = {
+	{"committer Vicent Marti tanoku@gmail.com> 123456 -0100 \n", "committer "},
+	{"author Vicent Marti <tanoku@gmail.com> 12345 \n", "author  "},
+	{"author Vicent Marti <tanoku@gmail.com> 12345 \n", "committer "},
+	{"author Vicent Marti 12345 \n", "author "},
+	{"author Vicent Marti <broken@email 12345 \n", "author "},
+	{"committer Vicent Marti ><\n", "committer "},
+	{"author ", "author "},
+   {NULL,NULL,}
+};
+
+void test_commit_parse__signature(void)
+{
+   passing_signature_test_case *passcase;
+   failing_signature_test_case *failcase;
+
+   for (passcase = passing_signature_cases; passcase->string != NULL; passcase++)
+   {
+      const char *str = passcase->string;
+      size_t len = strlen(passcase->string);
+      struct git_signature person = {NULL, NULL, {0, 0}};
+      cl_git_pass(git_signature__parse(&person, &str, str + len, passcase->header, '\n'));
+      cl_assert(strcmp(passcase->name, person.name) == 0);
+      cl_assert(strcmp(passcase->email, person.email) == 0);
+      cl_assert(passcase->time == person.when.time);
+      cl_assert(passcase->offset == person.when.offset);
+      git__free(person.name); git__free(person.email);
+   }
+
+   for (failcase = failing_signature_cases; failcase->string != NULL; failcase++)
+   {
+      const char *str = failcase->string;
+      size_t len = strlen(failcase->string);
+      git_signature person = {NULL, NULL, {0, 0}};
+      cl_git_fail(git_signature__parse(&person, &str, str + len, failcase->header, '\n'));
+      git__free(person.name); git__free(person.email);
+   }
+}
+
+
+
+static char *failing_commit_cases[] = {
+// empty commit
+"",
+// random garbage
+"asd97sa9du902e9a0jdsuusad09as9du098709aweu8987sd\n",
+// broken endlines 1
+"tree f6c0dad3c7b3481caa9d73db21f91964894a945b\r\n\
+parent 05452d6349abcd67aa396dfb28660d765d8b2a36\r\n\
+author Vicent Marti <tanoku@gmail.com> 1273848544 +0200\r\n\
+committer Vicent Marti <tanoku@gmail.com> 1273848544 +0200\r\n\
+\r\n\
+a test commit with broken endlines\r\n",
+// broken endlines 2
+"tree f6c0dad3c7b3481caa9d73db21f91964894a945b\
+parent 05452d6349abcd67aa396dfb28660d765d8b2a36\
+author Vicent Marti <tanoku@gmail.com> 1273848544 +0200\
+committer Vicent Marti <tanoku@gmail.com> 1273848544 +0200\
+\
+another test commit with broken endlines",
+// starting endlines
+"\ntree f6c0dad3c7b3481caa9d73db21f91964894a945b\n\
+parent 05452d6349abcd67aa396dfb28660d765d8b2a36\n\
+author Vicent Marti <tanoku@gmail.com> 1273848544 +0200\n\
+committer Vicent Marti <tanoku@gmail.com> 1273848544 +0200\n\
+\n\
+a test commit with a starting endline\n",
+// corrupted commit 1
+"tree f6c0dad3c7b3481caa9d73db21f91964894a945b\n\
+parent 05452d6349abcd67aa396df",
+// corrupted commit 2
+"tree f6c0dad3c7b3481caa9d73db21f91964894a945b\n\
+parent ",
+// corrupted commit 3
+"tree f6c0dad3c7b3481caa9d73db21f91964894a945b\n\
+parent ",
+// corrupted commit 4
+"tree f6c0dad3c7b3481caa9d73db21f91964894a945b\n\
+par",
+};
+
+
+static char *passing_commit_cases[] = {
+// simple commit with no message
+"tree 1810dff58d8a660512d4832e740f692884338ccd\n\
+author Vicent Marti <tanoku@gmail.com> 1273848544 +0200\n\
+committer Vicent Marti <tanoku@gmail.com> 1273848544 +0200\n\
+\n",
+// simple commit, no parent
+"tree 1810dff58d8a660512d4832e740f692884338ccd\n\
+author Vicent Marti <tanoku@gmail.com> 1273848544 +0200\n\
+committer Vicent Marti <tanoku@gmail.com> 1273848544 +0200\n\
+\n\
+a simple commit which works\n",
+// simple commit, no parent, no newline in message
+"tree 1810dff58d8a660512d4832e740f692884338ccd\n\
+author Vicent Marti <tanoku@gmail.com> 1273848544 +0200\n\
+committer Vicent Marti <tanoku@gmail.com> 1273848544 +0200\n\
+\n\
+a simple commit which works",
+// simple commit, 1 parent
+"tree 1810dff58d8a660512d4832e740f692884338ccd\n\
+parent e90810b8df3e80c413d903f631643c716887138d\n\
+author Vicent Marti <tanoku@gmail.com> 1273848544 +0200\n\
+committer Vicent Marti <tanoku@gmail.com> 1273848544 +0200\n\
+\n\
+a simple commit which works\n",
+};
+
+void test_commit_parse__entire_commit(void)
+{
+	const int broken_commit_count = sizeof(failing_commit_cases) / sizeof(*failing_commit_cases);
+	const int working_commit_count = sizeof(passing_commit_cases) / sizeof(*passing_commit_cases);
+	int i;
+
+	for (i = 0; i < broken_commit_count; ++i) {
+		git_commit *commit;
+		commit = (git_commit*)git__malloc(sizeof(git_commit));
+		memset(commit, 0x0, sizeof(git_commit));
+		commit->object.repo = g_repo;
+
+		cl_git_fail(git_commit__parse_buffer(
+                     commit,
+                     failing_commit_cases[i],
+                     strlen(failing_commit_cases[i]))
+         );
+
+		git_commit__free(commit);
+	}
+
+	for (i = 0; i < working_commit_count; ++i) {
+		git_commit *commit;
+
+		commit = (git_commit*)git__malloc(sizeof(git_commit));
+		memset(commit, 0x0, sizeof(git_commit));
+		commit->object.repo = g_repo;
+
+		cl_git_pass(git_commit__parse_buffer(
+                     commit,
+                     passing_commit_cases[i],
+                     strlen(passing_commit_cases[i]))
+         );
+
+		git_commit__free(commit);
+
+		commit = (git_commit*)git__malloc(sizeof(git_commit));
+		memset(commit, 0x0, sizeof(git_commit));
+		commit->object.repo = g_repo;
+
+		cl_git_pass(git_commit__parse_buffer(
+                     commit,
+                     passing_commit_cases[i],
+                     strlen(passing_commit_cases[i]))
+         );
+
+		git_commit__free(commit);
+	}
+}
+
+
+// query the details on a parsed commit
+void test_commit_parse__details0(void) {
+   static const char *commit_ids[] = {
+      "a4a7dce85cf63874e984719f4fdd239f5145052f", /* 0 */
+      "9fd738e8f7967c078dceed8190330fc8648ee56a", /* 1 */
+      "4a202b346bb0fb0db7eff3cffeb3c70babbd2045", /* 2 */
+      "c47800c7266a2be04c571c04d5a6614691ea99bd", /* 3 */
+      "8496071c1b46c854b31185ea97743be6a8774479", /* 4 */
+      "5b5b025afb0b4c913b4c338a42934a3863bf3644", /* 5 */
+      "a65fedf39aefe402d3bb6e24df4d4f5fe4547750", /* 6 */
+   };
+	const size_t commit_count = sizeof(commit_ids) / sizeof(const char *);
+   unsigned int i;
+
+	for (i = 0; i < commit_count; ++i) {
+		git_oid id;
+		git_commit *commit;
+
+		const git_signature *author, *committer;
+		const char *message;
+		git_time_t commit_time;
+		unsigned int parents, p;
+		git_commit *parent = NULL, *old_parent = NULL;
+
+		git_oid_fromstr(&id, commit_ids[i]);
+
+		cl_git_pass(git_commit_lookup(&commit, g_repo, &id));
+
+		message = git_commit_message(commit);
+		author = git_commit_author(commit);
+		committer = git_commit_committer(commit);
+		commit_time = git_commit_time(commit);
+		parents = git_commit_parentcount(commit);
+
+		cl_assert(strcmp(author->name, "Scott Chacon") == 0);
+		cl_assert(strcmp(author->email, "schacon@gmail.com") == 0);
+		cl_assert(strcmp(committer->name, "Scott Chacon") == 0);
+		cl_assert(strcmp(committer->email, "schacon@gmail.com") == 0);
+		cl_assert(message != NULL);
+		cl_assert(strchr(message, '\n') != NULL);
+		cl_assert(commit_time > 0);
+		cl_assert(parents <= 2);
+		for (p = 0;p < parents;p++) {
+			if (old_parent != NULL)
+				git_commit_free(old_parent);
+
+			old_parent = parent;
+			cl_git_pass(git_commit_parent(&parent, commit, p));
+			cl_assert(parent != NULL);
+			cl_assert(git_commit_author(parent) != NULL); // is it really a commit?
+		}
+		git_commit_free(old_parent);
+		git_commit_free(parent);
+
+		cl_git_fail(git_commit_parent(&parent, commit, parents));
+		git_commit_free(commit);
+	}
+}
+

tests-clar/commit/signature.c

@@ -0,0 +1,65 @@
+#include "clar_libgit2.h"
+
+static int try_build_signature(const char *name, const char *email, git_time_t time, int offset)
+{
+	git_signature *sign;
+	int error = GIT_SUCCESS;
+
+	if ((error =  git_signature_new(&sign, name, email, time, offset)) < GIT_SUCCESS)
+		return error;
+
+	git_signature_free((git_signature *)sign);
+
+	return error;
+}
+
+
+void test_commit_signature__create_trim(void)
+{
+   // creating a signature trims leading and trailing spaces
+   git_signature *sign;
+	cl_git_pass(git_signature_new(&sign, "  nulltoken ", "   emeric.fermas@gmail.com     ", 1234567890, 60));
+	cl_assert(strcmp(sign->name, "nulltoken") == 0);
+	cl_assert(strcmp(sign->email, "emeric.fermas@gmail.com") == 0);
+	git_signature_free((git_signature *)sign);
+}
+
+
+void test_commit_signature__create_empties(void)
+{
+   // can not create a signature with empty name or email
+	cl_git_pass(try_build_signature("nulltoken", "emeric.fermas@gmail.com", 1234567890, 60));
+
+	cl_git_fail(try_build_signature("", "emeric.fermas@gmail.com", 1234567890, 60));
+	cl_git_fail(try_build_signature("   ", "emeric.fermas@gmail.com", 1234567890, 60));
+	cl_git_fail(try_build_signature("nulltoken", "", 1234567890, 60));
+	cl_git_fail(try_build_signature("nulltoken", "  ", 1234567890, 60));
+}
+
+void test_commit_signature__create_one_char(void)
+{
+   // creating a one character signature
+	git_signature *sign;
+	cl_git_pass(git_signature_new(&sign, "x", "foo@bar.baz", 1234567890, 60));
+	cl_assert(strcmp(sign->name, "x") == 0);
+	cl_assert(strcmp(sign->email, "foo@bar.baz") == 0);
+	git_signature_free((git_signature *)sign);
+}
+
+void test_commit_signature__create_two_char(void)
+{
+   // creating a two character signature
+	git_signature *sign;
+	cl_git_pass(git_signature_new(&sign, "xx", "x@y.z", 1234567890, 60));
+	cl_assert(strcmp(sign->name, "xx") == 0);
+	cl_assert(strcmp(sign->email, "x@y.z") == 0);
+	git_signature_free((git_signature *)sign);
+}
+
+void test_commit_signature__create_zero_char(void)
+{
+   // creating a zero character signature
+	git_signature *sign;
+	cl_git_fail(git_signature_new(&sign, "", "x@y.z", 1234567890, 60));
+	cl_assert(sign == NULL);
+}

tests-clar/commit/write.c

@@ -0,0 +1,141 @@
+#include "clar_libgit2.h"
+
+static const char *committer_name = "Vicent Marti";
+static const char *committer_email = "vicent@github.com";
+static const char *commit_message = "This commit has been created in memory\n\
+   This is a commit created in memory and it will be written back to disk\n";
+static const char *tree_oid = "1810dff58d8a660512d4832e740f692884338ccd";
+static const char *root_commit_message = "This is a root commit\n\
+This is a root commit and should be the only one in this branch\n";
+
+
+// Fixture setup
+static git_repository *g_repo;
+void test_commit_write__initialize(void)
+{
+   g_repo = cl_git_sandbox_init("testrepo");
+}
+void test_commit_write__cleanup(void)
+{
+   cl_git_sandbox_cleanup();
+}
+
+
+// write a new commit object from memory to disk
+void test_commit_write__from_memory(void)
+{
+   git_commit *commit;
+   git_oid tree_id, parent_id, commit_id;
+   git_signature *author, *committer;
+   const git_signature *author1, *committer1;
+   git_commit *parent;
+   git_tree *tree;
+   const char *commit_id_str = "8496071c1b46c854b31185ea97743be6a8774479";
+
+   git_oid_fromstr(&tree_id, tree_oid);
+   cl_git_pass(git_tree_lookup(&tree, g_repo, &tree_id));
+
+   git_oid_fromstr(&parent_id, commit_id_str);
+   cl_git_pass(git_commit_lookup(&parent, g_repo, &parent_id));
+
+   /* create signatures */
+   cl_git_pass(git_signature_new(&committer, committer_name, committer_email, 123456789, 60));
+   cl_git_pass(git_signature_new(&author, committer_name, committer_email, 987654321, 90));
+
+   cl_git_pass(git_commit_create_v(
+      &commit_id, /* out id */
+      g_repo,
+      NULL, /* do not update the HEAD */
+      author,
+      committer,
+      NULL,
+      commit_message,
+      tree,
+      1, parent));
+
+   git_object_free((git_object *)parent);
+   git_object_free((git_object *)tree);
+
+   git_signature_free(committer);
+   git_signature_free(author);
+
+   cl_git_pass(git_commit_lookup(&commit, g_repo, &commit_id));
+
+   /* Check attributes were set correctly */
+   author1 = git_commit_author(commit);
+   cl_assert(author1 != NULL);
+   cl_assert(strcmp(author1->name, committer_name) == 0);
+   cl_assert(strcmp(author1->email, committer_email) == 0);
+   cl_assert(author1->when.time == 987654321);
+   cl_assert(author1->when.offset == 90);
+
+   committer1 = git_commit_committer(commit);
+   cl_assert(committer1 != NULL);
+   cl_assert(strcmp(committer1->name, committer_name) == 0);
+   cl_assert(strcmp(committer1->email, committer_email) == 0);
+   cl_assert(committer1->when.time == 123456789);
+   cl_assert(committer1->when.offset == 60);
+
+   cl_assert(strcmp(git_commit_message(commit), commit_message) == 0);
+
+#ifndef GIT_WIN32
+   cl_assert((loose_object_mode(REPOSITORY_FOLDER, (git_object *)commit) & 0777) == GIT_OBJECT_FILE_MODE);
+#endif
+}
+
+
+
+// create a root commit
+void test_commit_write__root(void)
+{
+	git_commit *commit;
+	git_oid tree_id, commit_id;
+	const git_oid *branch_oid;
+	git_signature *author, *committer;
+	const char *branch_name = "refs/heads/root-commit-branch";
+	git_reference *head, *branch;
+	char *head_old;
+	git_tree *tree;
+
+	git_oid_fromstr(&tree_id, tree_oid);
+	cl_git_pass(git_tree_lookup(&tree, g_repo, &tree_id));
+
+	/* create signatures */
+	cl_git_pass(git_signature_new(&committer, committer_name, committer_email, 123456789, 60));
+	cl_git_pass(git_signature_new(&author, committer_name, committer_email, 987654321, 90));
+
+	/* First we need to update HEAD so it points to our non-existant branch */
+	cl_git_pass(git_reference_lookup(&head, g_repo, "HEAD"));
+	cl_assert(git_reference_type(head) == GIT_REF_SYMBOLIC);
+	head_old = git__strdup(git_reference_target(head));
+	cl_assert(head_old != NULL);
+
+	cl_git_pass(git_reference_set_target(head, branch_name));
+
+	cl_git_pass(git_commit_create_v(
+		&commit_id, /* out id */
+		g_repo,
+		"HEAD",
+		author,
+		committer,
+		NULL,
+		root_commit_message,
+		tree,
+		0));
+
+	git_object_free((git_object *)tree);
+	git_signature_free(committer);
+	git_signature_free(author);
+
+	/*
+	 * The fact that creating a commit works has already been
+	 * tested. Here we just make sure it's our commit and that it was
+	 * written as a root commit.
+	 */
+	cl_git_pass(git_commit_lookup(&commit, g_repo, &commit_id));
+	cl_assert(git_commit_parentcount(commit) == 0);
+	cl_git_pass(git_reference_lookup(&branch, g_repo, branch_name));
+	branch_oid = git_reference_oid(branch);
+	cl_git_pass(git_oid_cmp(branch_oid, &commit_id));
+	cl_assert(!strcmp(git_commit_message(commit), root_commit_message));
+}