Add template dir and set gid to repo init

This extends git_repository_init_ext further with support for
initializing the repository from an external template directory
and with support for the "create shared" type flags that make a
set GID repository directory.

This also adds tests for much of the new functionality to the
existing `repo/init.c` test suite.

Also, this adds a bunch of new utility functions including a
very general purpose `git_futils_mkdir` (with the ability to
make paths and to chmod the paths post-creation) and a file
tree copying function `git_futils_cp_r`.  Also, this includes
some new path functions that were useful to keep the code
simple.

11 files changed, 594 insertions, 166 deletions

diff --git a/src/attr_file.c b/src/attr_file.c
index 20b3cf631..b2f312e3e 100644
--- a/src/attr_file.c
+++ b/src/attr_file.c
@@ -250,18 +250,15 @@ git_attr_assignment *git_attr_rule__lookup_assignment(
 int git_attr_path__init(
 	git_attr_path *info, const char *path, const char *base)
 {
+	ssize_t root;
+
 	/* build full path as best we can */
 	git_buf_init(&info->full, 0);
 
-	if (base != NULL && git_path_root(path) < 0) {
-		if (git_buf_joinpath(&info->full, base, path) < 0)
-			return -1;
-		info->path = info->full.ptr + strlen(base);
-	} else {
-		if (git_buf_sets(&info->full, path) < 0)
-			return -1;
-		info->path = info->full.ptr;
-	}
+	if (git_path_join_unrooted(&info->full, path, base, &root) < 0)
+		return -1;
+
+	info->path = info->full.ptr + root;
 
 	/* remove trailing slashes */
 	while (info->full.size > 0) {
diff --git a/src/config.c b/src/config.c
index 44cfe760c..3ca49714c 100644
--- a/src/config.c
+++ b/src/config.c
@@ -515,3 +515,28 @@ int git_config_open_global(git_config **out)
 	return error;
 }
 
+int git_config_open_outside_repo(git_config **out)
+{
+	int error;
+	git_config *cfg = NULL;
+	git_buf buf = GIT_BUF_INIT;
+
+	error = git_config_new(&cfg);
+
+	if (!error && !git_config_find_global_r(&buf))
+		error = git_config_add_file_ondisk(cfg, buf.ptr, 2);
+
+	if (!error && !git_config_find_system_r(&buf))
+		error = git_config_add_file_ondisk(cfg, buf.ptr, 1);
+
+	git_buf_free(&buf);
+
+	if (error && cfg) {
+		git_config_free(cfg);
+		cfg = NULL;
+	}
+
+	*out = cfg;
+
+	return error;
+}
diff --git a/src/fileops.c b/src/fileops.c
index 70c5c387c..5aa6632e0 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -10,19 +10,8 @@
 
 int git_futils_mkpath2file(const char *file_path, const mode_t mode)
 {
-	int result = 0;
-	git_buf target_folder = GIT_BUF_INIT;
-
-	if (git_path_dirname_r(&target_folder, file_path) < 0)
-		return -1;
-
-	/* Does the containing folder exist? */
-	if (git_path_isdir(target_folder.ptr) == false)
-		/* Let's create the tree structure */
-		result = git_futils_mkdir_r(target_folder.ptr, NULL, mode);
-
-	git_buf_free(&target_folder);
-	return result;
+	return git_futils_mkdir(
+		file_path, NULL, mode, GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST);
 }
 
 int git_futils_mktmp(git_buf *path_out, const char *filename)
@@ -239,76 +228,90 @@ void git_futils_mmap_free(git_map *out)
 	p_munmap(out);
 }
 
-int git_futils_mkdir_q(const char *path, const mode_t mode)
-{
-	if (p_mkdir(path, mode) < 0 && errno != EEXIST) {
-		giterr_set(GITERR_OS, "Failed to create directory at '%s'", path);
-		return -1;
-	}
-
-	return 0;
-}
-
-int git_futils_mkdir_r(const char *path, const char *base, const mode_t mode)
+int git_futils_mkdir(
+	const char *path,
+	const char *base,
+	mode_t mode,
+	uint32_t flags)
 {
 	git_buf make_path = GIT_BUF_INIT;
-	size_t start = 0;
-	char *pp, *sp;
-	bool failed = false;
-
-	if (base != NULL) {
-		/*
-		 * when a base is being provided, it is supposed to already exist.
-		 * Therefore, no attempt is being made to recursively create this leading path
-		 * segment. It's just skipped. */
-		start = strlen(base);
-		if (git_buf_joinpath(&make_path, base, path) < 0)
-			return -1;
-	} else {
-		int root_path_offset;
+	ssize_t root = 0;
+	char lastch, *tail;
 
-		if (git_buf_puts(&make_path, path) < 0)
-			return -1;
+	/* build path and find "root" where we should start calling mkdir */
+	if (git_path_join_unrooted(&make_path, path, base, &root) < 0)
+		return -1;
 
-		root_path_offset = git_path_root(make_path.ptr);
-		if (root_path_offset > 0) {
-			 /*
-			  * On Windows, will skip the drive name (eg. C: or D:)
-			  * or the leading part of a network path (eg. //computer_name ) */
-			start = root_path_offset;
-		}
+	if (make_path.size == 0) {
+		giterr_set(GITERR_OS, "Attempt to create empty path");
+		goto fail;
 	}
 
-	pp = make_path.ptr + start;
-
-	while (!failed && (sp = strchr(pp, '/')) != NULL) {
-		if (sp != pp && git_path_isdir(make_path.ptr) == false) {
-			*sp = 0;
-
-			/* Do not choke while trying to recreate an existing directory */
-			if (p_mkdir(make_path.ptr, mode) < 0 && errno != EEXIST)
-				failed = true;
+	/* remove trailing slashes on path */
+	while (make_path.ptr[make_path.size - 1] == '/') {
+		make_path.size--;
+		make_path.ptr[make_path.size] = '\0';
+	}
 
-			*sp = '/';
+	/* if we are not supposed to made the last element, truncate it */
+	if ((flags & GIT_MKDIR_SKIP_LAST) != 0)
+		git_buf_rtruncate_at_char(&make_path, '/');
+
+	/* if we are not supposed to make the whole path, reset root */
+	if ((flags & GIT_MKDIR_PATH) == 0)
+		root = git_buf_rfind(&make_path, '/');
+
+	/* clip root to make_path length */
+	if (root >= (ssize_t)make_path.size)
+		root = (ssize_t)make_path.size - 1;
+
+	tail = & make_path.ptr[root];
+
+	while (*tail) {
+		/* advance tail to include next path component */
+		while (*tail == '/')
+			tail++;
+		while (*tail && *tail != '/')
+			tail++;
+
+		/* truncate path at next component */
+		lastch = *tail;
+		*tail = '\0';
+
+		/* make directory */
+		if (p_mkdir(make_path.ptr, mode) < 0 &&
+			(errno != EEXIST || (flags & GIT_MKDIR_EXCL) != 0))
+		{
+			giterr_set(GITERR_OS, "Failed to make directory '%s'",
+				make_path.ptr);
+			goto fail;
 		}
 
-		pp = sp + 1;
-	}
+		/* chmod if requested */
+		if ((flags & GIT_MKDIR_CHMOD_PATH) != 0 ||
+			((flags & GIT_MKDIR_CHMOD) != 0 && lastch == '\0'))
+		{
+			if (p_chmod(make_path.ptr, mode) < 0) {
+				giterr_set(GITERR_OS, "Failed to set permissions on '%s'",
+					make_path.ptr);
+				goto fail;
+			}
+		}
 
-	if (*pp != '\0' && !failed) {
-		if (p_mkdir(make_path.ptr, mode) < 0 && errno != EEXIST)
-			failed = true;
+		*tail = lastch;
 	}
 
 	git_buf_free(&make_path);
+	return 0;
 
-	if (failed) {
-		giterr_set(GITERR_OS,
-			"Failed to create directory structure at '%s'", path);
-		return -1;
-	}
+fail:
+	git_buf_free(&make_path);
+	return -1;
+}
 
-	return 0;
+int git_futils_mkdir_r(const char *path, const char *base, const mode_t mode)
+{
+	return git_futils_mkdir(path, base, mode, GIT_MKDIR_PATH);
 }
 
 static int _rmdir_recurs_foreach(void *opaque, git_buf *path)
@@ -505,3 +508,202 @@ int git_futils_fake_symlink(const char *old, const char *new)
 	}
 	return retcode;
 }
+
+static int git_futils_cp_fd(int ifd, int ofd, bool close_fd)
+{
+	int error = 0;
+	char buffer[4096];
+	ssize_t len = 0;
+
+	while (!error && (len = p_read(ifd, buffer, sizeof(buffer))) > 0)
+		/* p_write() does not have the same semantics as write().  It loops
+		 * internally and will return 0 when it has completed writing.
+		 */
+		error = p_write(ofd, buffer, len);
+
+	if (len < 0) {
+		giterr_set(GITERR_OS, "Read error while copying file");
+		error = (int)len;
+	}
+
+	if (close_fd) {
+		p_close(ifd);
+		p_close(ofd);
+	}
+
+	return error;
+}
+
+int git_futils_cp_withpath(
+	const char *from, const char *to, mode_t filemode, mode_t dirmode)
+{
+	int ifd, ofd;
+
+	if (git_futils_mkpath2file(to, dirmode) < 0)
+		return -1;
+
+	if ((ifd = git_futils_open_ro(from)) < 0)
+		return ifd;
+
+	if ((ofd = p_open(to, O_WRONLY | O_CREAT | O_EXCL, filemode)) < 0) {
+		if (errno == ENOENT || errno == ENOTDIR)
+			ofd = GIT_ENOTFOUND;
+		giterr_set(GITERR_OS, "Failed to open '%s' for writing", to);
+		p_close(ifd);
+		return ofd;
+	}
+
+	return git_futils_cp_fd(ifd, ofd, true);
+}
+
+static int git_futils_cplink(
+	const char *from, size_t from_filesize, const char *to)
+{
+	int error = 0;
+	ssize_t read_len;
+	char *link_data = git__malloc(from_filesize + 1);
+	GITERR_CHECK_ALLOC(link_data);
+
+	read_len = p_readlink(from, link_data, from_filesize);
+	if (read_len != (ssize_t)from_filesize) {
+		giterr_set(GITERR_OS, "Failed to read symlink data for '%s'", from);
+		error = -1;
+	}
+	else {
+		link_data[read_len] = '\0';
+
+		if (p_symlink(link_data, to) < 0) {
+			giterr_set(GITERR_OS, "Could not symlink '%s' as '%s'",
+				link_data, to);
+			error = -1;
+		}
+	}
+
+	git__free(link_data);
+	return error;
+}
+
+typedef struct {
+	const char *to_root;
+	git_buf to;
+	ssize_t from_prefix;
+	uint32_t flags;
+	uint32_t mkdir_flags;
+	mode_t dirmode;
+} cp_r_info;
+
+static int _cp_r_callback(void *ref, git_buf *from)
+{
+	cp_r_info *info = ref;
+	struct stat from_st, to_st;
+	bool exists = false;
+
+	if ((info->flags & GIT_CPDIR_COPY_DOTFILES) == 0 &&
+		from->ptr[git_path_basename_offset(from)] == '.')
+		return 0;
+
+	if (git_buf_joinpath(
+			&info->to, info->to_root, from->ptr + info->from_prefix) < 0)
+		return -1;
+
+	if (p_lstat(info->to.ptr, &to_st) < 0) {
+		if (errno != ENOENT) {
+			giterr_set(GITERR_OS,
+				"Could not access %s while copying files", info->to.ptr);
+			return -1;
+		}
+	} else
+		exists = true;
+
+	if (git_path_lstat(from->ptr, &from_st) < 0)
+		return -1;
+
+	if (S_ISDIR(from_st.st_mode)) {
+		int error = 0;
+		mode_t oldmode = info->dirmode;
+
+		/* if we are not chmod'ing, then overwrite dirmode */
+		if ((info->flags & GIT_CPDIR_CHMOD) == 0)
+			info->dirmode = from_st.st_mode;
+
+		/* make directory now if CREATE_EMPTY_DIRS is requested and needed */
+		if (!exists && (info->flags & GIT_CPDIR_CREATE_EMPTY_DIRS) != 0)
+			error = git_futils_mkdir(
+				info->to.ptr, NULL, info->dirmode, info->mkdir_flags);
+
+		/* recurse onto target directory */
+		if (!exists || S_ISDIR(to_st.st_mode))
+			error = git_path_direach(from, _cp_r_callback, info);
+
+		if (oldmode != 0)
+			info->dirmode = oldmode;
+
+		return error;
+	}
+
+	if (exists) {
+		if ((info->flags & GIT_CPDIR_OVERWRITE) == 0)
+			return 0;
+
+		if (p_unlink(info->to.ptr) < 0) {
+			giterr_set(GITERR_OS, "Cannot overwrite existing file '%s'",
+				info->to.ptr);
+			return -1;
+		}
+	}
+
+	/* Done if this isn't a regular file or a symlink */
+	if (!S_ISREG(from_st.st_mode) &&
+		(!S_ISLNK(from_st.st_mode) ||
+		 (info->flags & GIT_CPDIR_COPY_SYMLINKS) == 0))
+		return 0;
+
+	/* Make container directory on demand if needed */
+	if ((info->flags & GIT_CPDIR_CREATE_EMPTY_DIRS) == 0 &&
+		git_futils_mkdir(
+			info->to.ptr, NULL, info->dirmode, info->mkdir_flags) < 0)
+		return -1;
+
+	/* make symlink or regular file */
+	if (S_ISLNK(from_st.st_mode))
+		return git_futils_cplink(from->ptr, from_st.st_size, info->to.ptr);
+	else
+		return git_futils_cp_withpath(
+			from->ptr, info->to.ptr, from_st.st_mode, info->dirmode);
+}
+
+int git_futils_cp_r(
+	const char *from,
+	const char *to,
+	uint32_t flags,
+	mode_t dirmode)
+{
+	int error;
+	git_buf path = GIT_BUF_INIT;
+	cp_r_info info;
+
+	if (git_buf_sets(&path, from) < 0)
+		return -1;
+
+	info.to_root = to;
+	info.flags   = flags;
+	info.dirmode = dirmode;
+	info.from_prefix = path.size;
+	git_buf_init(&info.to, 0);
+
+	/* precalculate mkdir flags */
+	if ((flags & GIT_CPDIR_CREATE_EMPTY_DIRS) == 0) {
+		info.mkdir_flags = GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST;
+		if ((flags & GIT_CPDIR_CHMOD) != 0)
+			info.mkdir_flags |= GIT_MKDIR_CHMOD_PATH;
+	} else {
+		info.mkdir_flags =
+			((flags & GIT_CPDIR_CHMOD) != 0) ? GIT_MKDIR_CHMOD : 0;
+	}
+
+	error = _cp_r_callback(&info, &path);
+
+	git_buf_free(&path);
+
+	return error;
+}
diff --git a/src/fileops.h b/src/fileops.h
index edfcb7dd0..6f3450373 100644
--- a/src/fileops.h
+++ b/src/fileops.h
@@ -48,17 +48,47 @@ extern int git_futils_creat_locked(const char *path, const mode_t mode);
 extern int git_futils_creat_locked_withpath(const char *path, const mode_t dirmode, const mode_t mode);
 
 /**
- * Create a directory if it does not exist
+ * Create a path recursively
+ *
+ * If a base parameter is being passed, it's expected to be valued with a
+ * path pointing to an already existing directory.
  */
-extern int git_futils_mkdir_q(const char *path, const mode_t mode);
+extern int git_futils_mkdir_r(const char *path, const char *base, const mode_t mode);
 
 /**
- * Create a path recursively
+ * Flags to pass to `git_futils_mkdir`.
  *
- * If a base parameter is being passed, it's expected to be valued with a path pointing to an already
- * exisiting directory.
+ * * GIT_MKDIR_EXCL is "exclusive" - i.e. generate an error if dir exists.
+ * * GIT_MKDIR_PATH says to make all components in the path.
+ * * GIT_MKDIR_CHMOD says to chmod the final directory entry after creation
+ * * GIT_MKDIR_CHMOD_PATH says to chmod each directory component in the path
+ * * GIT_MKDIR_SKIP_LAST says to leave off the last element of the path
+ *
+ * Note that the chmod options will be executed even if the directory already
+ * exists, unless GIT_MKDIR_EXCL is given.
  */
-extern int git_futils_mkdir_r(const char *path, const char *base, const mode_t mode);
+typedef enum {
+	GIT_MKDIR_EXCL = 1,
+	GIT_MKDIR_PATH = 2,
+	GIT_MKDIR_CHMOD = 4,
+	GIT_MKDIR_CHMOD_PATH = 8,
+	GIT_MKDIR_SKIP_LAST = 16
+} git_futils_mkdir_flags;
+
+/**
+ * Create a directory or entire path.
+ *
+ * This makes a directory (and the entire path leading up to it if requested),
+ * and optionally chmods the directory immediately after (or each part of the
+ * path if requested).
+ *
+ * @param path The path to create.
+ * @param base Root for relative path.  These directories will never be made.
+ * @param mode The mode to use for created directories.
+ * @param flags Combination of the mkdir flags above.
+ * @return 0 on success, else error code
+ */
+extern int git_futils_mkdir(const char *path, const char *base, mode_t mode, uint32_t flags);
 
 /**
  * Create all the folders required to contain
@@ -100,6 +130,47 @@ extern int git_futils_mktmp(git_buf *path_out, const char *filename);
 extern int git_futils_mv_withpath(const char *from, const char *to, const mode_t dirmode);
 
 /**
+ * Copy a file, creating the destination path if needed.
+ *
+ * The filemode will be used for the file and the dirmode will be used for
+ * any intervening directories if necessary.
+ */
+extern int git_futils_cp_withpath(
+	const char *from,
+	const char *to,
+	mode_t filemode,
+	mode_t dirmode);
+
+/**
+ * Flags that can be passed to `git_futils_cp_r`.
+ */
+typedef enum {
+	GIT_CPDIR_CREATE_EMPTY_DIRS = 1,
+	GIT_CPDIR_COPY_SYMLINKS = 2,
+	GIT_CPDIR_COPY_DOTFILES = 4,
+	GIT_CPDIR_OVERWRITE = 8,
+	GIT_CPDIR_CHMOD = 16
+} git_futils_cpdir_flags;
+
+/**
+ * Copy a directory tree.
+ *
+ * This copies directories and files from one root to another.  You can
+ * pass a combinationof GIT_CPDIR flags as defined above.
+ *
+ * If you pass the CHMOD flag, then the dirmode will be applied to all
+ * directories that are created during the copy, overiding the natural
+ * permissions.  If you do not pass the CHMOD flag, then the dirmode
+ * will actually be copied from the source files and the `dirmode` arg
+ * will be ignored.
+ */
+extern int git_futils_cp_r(
+	const char *from,
+	const char *to,
+	uint32_t flags,
+	mode_t dirmode);
+
+/**
  * Open a file readonly and set error if needed.
  */
 extern int git_futils_open_ro(const char *path);
diff --git a/src/path.c b/src/path.c
index 22391c52b..15188850d 100644
--- a/src/path.c
+++ b/src/path.c
@@ -147,6 +147,20 @@ char *git_path_basename(const char *path)
 	return basename;
 }
 
+size_t git_path_basename_offset(git_buf *buffer)
+{
+	ssize_t slash;
+
+	if (!buffer || buffer->size <= 0)
+		return 0;
+
+	slash = git_buf_rfind_next(buffer, '/');
+
+	if (slash >= 0 && buffer->ptr[slash] == '/')
+		return (size_t)(slash + 1);
+
+	return 0;
+}
 
 const char *git_path_topdir(const char *path)
 {
@@ -193,6 +207,31 @@ int git_path_root(const char *path)
 	return -1;	/* Not a real error - signals that path is not rooted */
 }
 
+int git_path_join_unrooted(
+	git_buf *path_out, const char *path, const char *base, ssize_t *root_at)
+{
+	int error, root;
+
+	assert(path && path_out);
+
+	root = git_path_root(path);
+
+	if (base != NULL && root < 0) {
+		error = git_buf_joinpath(path_out, base, path);
+
+		if (root_at)
+			*root_at = (ssize_t)strlen(base);
+	}
+	else {
+		error = git_buf_sets(path_out, path);
+
+		if (root_at)
+			*root_at = (root < 0) ? 0 : (ssize_t)root;
+	}
+
+	return error;
+}
+
 int git_path_prettify(git_buf *path_out, const char *path, const char *base)
 {
 	char buf[GIT_PATH_MAX];
@@ -502,12 +541,7 @@ bool git_path_contains_file(git_buf *base, const char *file)
 
 int git_path_find_dir(git_buf *dir, const char *path, const char *base)
 {
-	int error;
-
-	if (base != NULL && git_path_root(path) < 0)
-		error = git_buf_joinpath(dir, base, path);
-	else
-		error = git_buf_sets(dir, path);
+	int error = git_path_join_unrooted(dir, path, base, NULL);
 
 	if (!error) {
 		char buf[GIT_PATH_MAX];
diff --git a/src/path.h b/src/path.h
index 14618b2fc..b6292277f 100644
--- a/src/path.h
+++ b/src/path.h
@@ -58,6 +58,11 @@ extern int git_path_dirname_r(git_buf *buffer, const char *path);
 extern char *git_path_basename(const char *path);
 extern int git_path_basename_r(git_buf *buffer, const char *path);
 
+/* Return the offset of the start of the basename.  Unlike the other
+ * basename functions, this returns 0 if the path is empty.
+ */
+extern size_t git_path_basename_offset(git_buf *buffer);
+
 extern const char *git_path_topdir(const char *path);
 
 /**
@@ -186,6 +191,15 @@ extern bool git_path_contains_dir(git_buf *parent, const char *subdir);
 extern bool git_path_contains_file(git_buf *dir, const char *file);
 
 /**
+ * Prepend base to unrooted path or just copy path over.
+ *
+ * This will optionally return the index into the path where the "root"
+ * is, either the end of the base directory prefix or the path root.
+ */
+extern int git_path_join_unrooted(
+	git_buf *path_out, const char *path, const char *base, ssize_t *root_at);
+
+/**
  * Clean up path, prepending base if it is not already rooted.
  */
 extern int git_path_prettify(git_buf *path_out, const char *path, const char *base);
diff --git a/src/posix.h b/src/posix.h
index d35fe08a5..71bb82283 100644
--- a/src/posix.h
+++ b/src/posix.h
@@ -11,8 +11,15 @@
 #include <fcntl.h>
 #include <time.h>
 
+#ifndef S_IFGITLINK
 #define S_IFGITLINK 0160000
 #define S_ISGITLINK(m) (((m) & S_IFMT) == S_IFGITLINK)
+#endif
+
+/* if S_ISGID is not defined, then don't try to set it */
+#ifndef S_ISGID
+#define S_ISGID 0
+#endif
 
 #if !defined(O_BINARY)
 #define O_BINARY 0
diff --git a/src/repository.c b/src/repository.c
index 994b13bd5..ebd60360a 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -24,6 +24,8 @@
 
 #define GIT_REPO_VERSION 0
 
+#define GIT_TEMPLATE_DIR "/usr/share/git-core/templates"
+
 static void drop_odb(git_repository *repo)
 {
 	if (repo->_odb != NULL) {
@@ -681,6 +683,7 @@ static bool is_chmod_supported(const char *file_path)
 		return false;
 
 	_is_supported = (st1.st_mode != st2.st_mode);
+
 	return _is_supported;
 }
 
@@ -702,20 +705,45 @@ cleanup:
 	return _is_insensitive;
 }
 
+static bool are_symlinks_supported(const char *wd_path)
+{
+	git_buf path = GIT_BUF_INIT;
+	int fd;
+	struct stat st;
+	static int _symlinks_supported = -1;
+
+	if (_symlinks_supported > -1)
+		return _symlinks_supported;
+
+	if ((fd = git_futils_mktmp(&path, wd_path)) < 0 ||
+		p_close(fd) < 0 ||
+		p_unlink(path.ptr) < 0 ||
+		p_symlink("testing", path.ptr) < 0 ||
+		p_lstat(path.ptr, &st) < 0)
+		_symlinks_supported = false;
+	else
+		_symlinks_supported = (S_ISLNK(st.st_mode) != 0);
+
+	(void)p_unlink(path.ptr);
+	git_buf_free(&path);
+
+	return _symlinks_supported;
+}
+
 static int repo_init_config(
-	const char *git_dir, git_repository_init_options *opts)
+	const char *repo_dir,
+	const char *work_dir,
+	git_repository_init_options *opts)
 {
+	int error = 0;
 	git_buf cfg_path = GIT_BUF_INIT;
 	git_config *config = NULL;
 
-#define SET_REPO_CONFIG(type, name, val) {\
-	if (git_config_set_##type(config, name, val) < 0) { \
-		git_buf_free(&cfg_path); \
-		git_config_free(config); \
-		return -1; } \
-}
+#define SET_REPO_CONFIG(TYPE, NAME, VAL) do {\
+	if ((error = git_config_set_##TYPE(config, NAME, VAL)) < 0) \
+		goto cleanup; } while (0)
 
-	if (git_buf_joinpath(&cfg_path, git_dir, GIT_CONFIG_FILENAME_INREPO) < 0)
+	if (git_buf_joinpath(&cfg_path, repo_dir, GIT_CONFIG_FILENAME_INREPO) < 0)
 		return -1;
 
 	if (git_config_open_ondisk(&config, git_buf_cstr(&cfg_path)) < 0) {
@@ -724,12 +752,8 @@ static int repo_init_config(
 	}
 
 	if ((opts->flags & GIT_REPOSITORY_INIT__IS_REINIT) != 0 &&
-		check_repositoryformatversion(config) < 0)
-	{
-		git_buf_free(&cfg_path);
-		git_config_free(config);
-		return -1;
-	}
+		(error = check_repositoryformatversion(config)) < 0)
+		goto cleanup;
 
 	SET_REPO_CONFIG(
 		bool, "core.bare", (opts->flags & GIT_REPOSITORY_INIT_BARE) != 0);
@@ -738,25 +762,42 @@ static int repo_init_config(
 	SET_REPO_CONFIG(
 		bool, "core.filemode", is_chmod_supported(git_buf_cstr(&cfg_path)));
 
-	if (!(opts->flags & GIT_REPOSITORY_INIT_BARE))
+	if (!(opts->flags & GIT_REPOSITORY_INIT_BARE)) {
 		SET_REPO_CONFIG(bool, "core.logallrefupdates", true);
 
+		if (!are_symlinks_supported(work_dir))
+			SET_REPO_CONFIG(bool, "core.symlinks", false);
+
+		if (!(opts->flags & GIT_REPOSITORY_INIT__NATURAL_WD)) {
+			SET_REPO_CONFIG(string, "core.worktree", work_dir);
+		}
+		else if ((opts->flags & GIT_REPOSITORY_INIT__IS_REINIT) != 0) {
+			if ((error = git_config_delete(config, "core.worktree")) < 0)
+				goto cleanup;
+		}
+	} else {
+		if (!are_symlinks_supported(repo_dir))
+			SET_REPO_CONFIG(bool, "core.symlinks", false);
+	}
+
 	if (!(opts->flags & GIT_REPOSITORY_INIT__IS_REINIT) &&
-		is_filesystem_case_insensitive(git_dir))
+		is_filesystem_case_insensitive(repo_dir))
 		SET_REPO_CONFIG(bool, "core.ignorecase", true);
 
-	if (opts->flags & GIT_REPOSITORY_INIT_SHARED_GROUP) {
+	if (opts->mode == GIT_REPOSITORY_INIT_SHARED_GROUP) {
 		SET_REPO_CONFIG(int32, "core.sharedrepository", 1);
 		SET_REPO_CONFIG(bool, "receive.denyNonFastforwards", true);
-	} else if (opts->flags & GIT_REPOSITORY_INIT_SHARED_ALL) {
+	}
+	else if (opts->mode == GIT_REPOSITORY_INIT_SHARED_ALL) {
 		SET_REPO_CONFIG(int32, "core.sharedrepository", 2);
 		SET_REPO_CONFIG(bool, "receive.denyNonFastforwards", true);
 	}
 
+cleanup:
 	git_buf_free(&cfg_path);
 	git_config_free(config);
 
-	return 0;
+	return error;
 }
 
 static int repo_write_template(
@@ -848,6 +889,17 @@ cleanup:
 	return error;
 }
 
+static mode_t pick_dir_mode(git_repository_init_options *opts)
+{
+	if (opts->mode == GIT_REPOSITORY_INIT_SHARED_UMASK)
+		return 0755;
+	if (opts->mode == GIT_REPOSITORY_INIT_SHARED_GROUP)
+		return (0775 | S_ISGID);
+	if (opts->mode == GIT_REPOSITORY_INIT_SHARED_ALL)
+		return (0777 | S_ISGID);
+	return opts->mode;
+}
+
 #include "repo_template.h"
 
 static int repo_init_structure(
@@ -855,8 +907,11 @@ static int repo_init_structure(
 	const char *work_dir,
 	git_repository_init_options *opts)
 {
+	int error = 0;
 	repo_template_item *tpl;
-	mode_t gid = 0;
+	bool external_tpl =
+		((opts->flags & GIT_REPOSITORY_INIT_EXTERNAL_TEMPLATE) != 0);
+	mode_t dmode = pick_dir_mode(opts);
 
 	/* Hide the ".git" directory */
 	if ((opts->flags & GIT_REPOSITORY_INIT_BARE) != 0) {
@@ -874,32 +929,60 @@ static int repo_init_structure(
 			return -1;
 	}
 
-	if ((opts->flags & GIT_REPOSITORY_INIT_SHARED_GROUP) != 0 ||
-		(opts->flags & GIT_REPOSITORY_INIT_SHARED_ALL) != 0)
-		gid = S_ISGID;
+	/* Copy external template if requested */
+	if (external_tpl) {
+		git_config *cfg;
+		const char *tdir;
 
-	/* TODO: honor GIT_REPOSITORY_INIT_USE_EXTERNAL_TEMPLATE if set */
+		if (opts->template_path)
+			tdir = opts->template_path;
+		else if ((error = git_config_open_outside_repo(&cfg)) < 0)
+			return error;
+		else {
+			error = git_config_get_string(&tdir, cfg, "init.templatedir");
 
-	/* Copy internal template as needed */
+			git_config_free(cfg);
 
-	for (tpl = repo_template; tpl->path; ++tpl) {
-		if (!tpl->content) {
-			if (git_futils_mkdir_r(tpl->path, repo_dir, tpl->mode | gid) < 0)
-				return -1;
+			if (error && error != GIT_ENOTFOUND)
+				return error;
+
+			giterr_clear();
+			tdir = GIT_TEMPLATE_DIR;
 		}
-		else {
+
+		error = git_futils_cp_r(tdir, repo_dir,
+			GIT_CPDIR_COPY_SYMLINKS | GIT_CPDIR_CHMOD, dmode);
+
+		if (error < 0) {
+			if (strcmp(tdir, GIT_TEMPLATE_DIR) != 0)
+				return error;
+
+			/* if template was default, ignore error and use internal */
+			giterr_clear();
+			external_tpl = false;
+		}
+	}
+
+	/* Copy internal template
+	 * - always ensure existence of dirs
+	 * - only create files if no external template was specified
+	 */
+	for (tpl = repo_template; !error && tpl->path; ++tpl) {
+		if (!tpl->content)
+			error = git_futils_mkdir(
+				tpl->path, repo_dir, dmode, GIT_MKDIR_PATH | GIT_MKDIR_CHMOD);
+		else if (!external_tpl) {
 			const char *content = tpl->content;
 
 			if (opts->description && strcmp(tpl->path, GIT_DESC_FILE) == 0)
 				content = opts->description;
 
-			if (repo_write_template(
-					repo_dir, false, tpl->path, tpl->mode, false, content) < 0)
-				return -1;
+			error = repo_write_template(
+				repo_dir, false, tpl->path, tpl->mode, false, content);
 		}
 	}
 
-	return 0;
+	return error;
 }
 
 static int repo_init_directories(
@@ -910,6 +993,7 @@ static int repo_init_directories(
 {
 	int error = 0;
 	bool add_dotgit, has_dotgit, natural_wd;
+	mode_t dirmode;
 
 	/* set up repo path */
 
@@ -930,15 +1014,9 @@ static int repo_init_directories(
 
 	if ((opts->flags & GIT_REPOSITORY_INIT_BARE) == 0) {
 		if (opts->workdir_path) {
-			if (git_path_root(opts->workdir_path) < 0) {
-				if (git_path_dirname_r(wd_path, repo_path->ptr) < 0 ||
-					git_buf_putc(wd_path, '/') < 0 ||
-					git_buf_puts(wd_path, opts->workdir_path) < 0)
-					return -1;
-			} else {
-				if (git_buf_sets(wd_path, opts->workdir_path) < 0)
-					return -1;
-			}
+			if (git_path_join_unrooted(
+					wd_path, opts->workdir_path, repo_path->ptr, NULL) < 0)
+				return -1;
 		} else if (has_dotgit) {
 			if (git_path_dirname_r(wd_path, repo_path->ptr) < 0)
 				return -1;
@@ -962,43 +1040,33 @@ static int repo_init_directories(
 	if (natural_wd)
 		opts->flags |= GIT_REPOSITORY_INIT__NATURAL_WD;
 
-	/* pick mode */
-
-	if ((opts->flags & GIT_REPOSITORY_INIT_SHARED_CUSTOM) != 0)
-		/* leave mode as is */;
-	else if ((opts->flags & GIT_REPOSITORY_INIT_SHARED_GROUP) != 0)
-		opts->mode = 0775 | S_ISGID;
-	else if ((opts->flags & GIT_REPOSITORY_INIT_SHARED_ALL) != 0)
-		opts->mode = 0777 | S_ISGID;
-	else if ((opts->flags & GIT_REPOSITORY_INIT_BARE) != 0)
-		opts->mode = 0755;
-	else
-		opts->mode = 0755;
-
 	/* create directories as needed / requested */
 
-	if ((opts->flags & GIT_REPOSITORY_INIT_MKPATH) != 0) {
-		error = git_futils_mkdir_r(repo_path->ptr, NULL, opts->mode);
+	dirmode = pick_dir_mode(opts);
 
-		if (!error && !natural_wd && wd_path->size > 0)
-			error = git_futils_mkdir_r(wd_path->ptr, NULL, opts->mode);
+	if ((opts->flags & GIT_REPOSITORY_INIT_MKDIR) != 0 && has_dotgit) {
+		git_buf p = GIT_BUF_INIT;
+		if ((error = git_path_dirname_r(&p, repo_path->ptr)) >= 0)
+			error = git_futils_mkdir(p.ptr, NULL, dirmode, 0);
+		git_buf_free(&p);
 	}
-	else if ((opts->flags & GIT_REPOSITORY_INIT_MKDIR) != 0) {
-		if (has_dotgit) {
-			git_buf p = GIT_BUF_INIT;
-			if ((error = git_path_dirname_r(&p, repo_path->ptr)) >= 0)
-				error = git_futils_mkdir_q(p.ptr, opts->mode);
-			git_buf_free(&p);
-		}
 
-		if (!error)
-			error = git_futils_mkdir_q(repo_path->ptr, opts->mode);
-
-		if (!error && !natural_wd && wd_path->size > 0)
-			error = git_futils_mkdir_q(wd_path->ptr, opts->mode);
+	if ((opts->flags & GIT_REPOSITORY_INIT_MKDIR) != 0 ||
+		(opts->flags & GIT_REPOSITORY_INIT_MKPATH) != 0 ||
+		has_dotgit)
+	{
+		uint32_t mkflag = GIT_MKDIR_CHMOD;
+		if ((opts->flags & GIT_REPOSITORY_INIT_MKPATH) != 0)
+			mkflag |= GIT_MKDIR_PATH;
+		error = git_futils_mkdir(repo_path->ptr, NULL, dirmode, mkflag);
 	}
-	else if (has_dotgit)
-		error = git_futils_mkdir_q(repo_path->ptr, opts->mode);
+
+	if (wd_path->size > 0 &&
+		!natural_wd &&
+		((opts->flags & GIT_REPOSITORY_INIT_MKDIR) != 0 ||
+		 (opts->flags & GIT_REPOSITORY_INIT_MKPATH) != 0))
+		error = git_futils_mkdir(wd_path->ptr, NULL, dirmode & ~S_ISGID,
+			(opts->flags & GIT_REPOSITORY_INIT_MKPATH) ? GIT_MKDIR_PATH : 0);
 
 	/* prettify both directories now that they are created */
 
@@ -1063,14 +1131,16 @@ int git_repository_init_ext(
 
 		opts->flags |= GIT_REPOSITORY_INIT__IS_REINIT;
 
-		error = repo_init_config(git_buf_cstr(&repo_path), opts);
+		error = repo_init_config(
+			git_buf_cstr(&repo_path), git_buf_cstr(&wd_path), opts);
 
 		/* TODO: reinitialize the templates */
 	}
 	else {
 		if (!(error = repo_init_structure(
 				git_buf_cstr(&repo_path), git_buf_cstr(&wd_path), opts)) &&
-			!(error = repo_init_config(git_buf_cstr(&repo_path), opts)))
+			!(error = repo_init_config(
+				git_buf_cstr(&repo_path), git_buf_cstr(&wd_path), opts)))
 			error = repo_init_create_head(
 				git_buf_cstr(&repo_path), opts->initial_head);
 	}
diff --git a/src/repository.h b/src/repository.h
index dd42c63e1..4695edf3a 100644
--- a/src/repository.h
+++ b/src/repository.h
@@ -75,7 +75,6 @@ enum {
 	GIT_REPOSITORY_INIT__IS_REINIT  = (1u << 18),
 };
 
-
 /** Base git object for inheritance */
 struct git_object {
 	git_cached_obj cached;
diff --git a/src/unix/posix.h b/src/unix/posix.h
index 7a3a388ec..45d2b7238 100644
--- a/src/unix/posix.h
+++ b/src/unix/posix.h
@@ -18,6 +18,7 @@
 
 #define p_lstat(p,b) lstat(p,b)
 #define p_readlink(a, b, c) readlink(a, b, c)
+#define p_symlink(o,n) symlink(o, n)
 #define p_link(o,n) link(o, n)
 #define p_symlink(o,n) symlink(o,n)
 #define p_unlink(p) unlink(p)
diff --git a/src/win32/posix.h b/src/win32/posix.h
index 14caae418..def3a766a 100644
--- a/src/win32/posix.h
+++ b/src/win32/posix.h
@@ -19,6 +19,14 @@ GIT_INLINE(int) p_link(const char *old, const char *new)
 	return -1;
 }
 
+GIT_INLINE(int) p_symlink(const char *old, const char *new)
+{
+	GIT_UNUSED(old);
+	GIT_UNUSED(new);
+	errno = ENOSYS;
+	return -1;
+}
+
 GIT_INLINE(int) p_mkdir(const char *path, mode_t mode)
 {
 	wchar_t* buf = gitwin_to_utf16(path);