git_repository_init_ext and git_clone fail with path too long

[pde-cds]

Regarding libgit2/libgit2sharp#2051

Reproduction steps

When using git_repository_init_ext and git_clone on a path which is longer than 260, it will fail with path too long

Expected behavior

work like expected

Actual behavior

path too long

Version of libgit2 (release number or SHA1)

1.6.4 through LibGit2Sharp.NativeBinaries 2.0.320

Operating system(s) tested

Win 10 22H2

[ethomson]

Is this a libgit2 problem or a LibGit2Sharp problem? If it's the former, can you provide repro steps?

[pde-cds]

I can reproduce it through LibGit2Sharp, but the error comes from libgit2.
Because of this, I created this issue additionally to the one in libgit2sharp

[ethomson]

Did you read this documentation?

libgit2/docs/win32-longpaths.md

Line 2 in 9903482

======================

[pde-cds]

Well thats nice to now. As coming from LibGit2Sharp there was no such information
Never the less we used a modified version of 0.26.2 with usage of libgit2 with ianhattendorf's changes (#5347) and preset of GIT_OPT_SET_WINDOWS_LONGPATHS with this version there were no problems with an git repo in a path longer than 260.
So the behaviour of this has changed since.
Regarding the Windows 260 char problems: Shouldn't be handled by the OS/filesystem if those path cannot be worked with?
Is there a need to restrict the path inside of libgit2?

[pde-cds]

After testing some changes in libgit2, I found our problem which seems to be util/fs_path.c/git_fs_path_validate_str_length_with_suffix

libgit2/src/util/fs_path.c

Lines 1727 to 1748 in 42b5d85

	int git_fs_path_validate_str_length_with_suffix(
	git_str *path,
	size_t suffix_len)
	{
	#ifdef GIT_WIN32
	size_t utf8_len = git_utf8_char_length(path->ptr, path->size);
	size_t total_len;
	if (GIT_ADD_SIZET_OVERFLOW(&total_len, utf8_len, suffix_len) ||
	total_len > MAX_PATH) {
	git_error_set(GIT_ERROR_FILESYSTEM, "path too long: '%.*s'",
	(int)path->size, path->ptr);
	return -1;
	}
	#else
	GIT_UNUSED(path);
	GIT_UNUSED(suffix_len);
	#endif
	return 0;
	}

Removing || total_len > MAX_PATH from the if clause fixed our problem.
This code is potentially duplicated by

libgit2/src/util/fs_path.h

Lines 683 to 709 in 42b5d85

	/**
	* Validate an on-disk path, taking into account that it will have a
	* suffix appended (eg, `.lock`).
	*/
	GIT_INLINE(int) git_fs_path_validate_filesystem_with_suffix(
	const char *path,
	size_t path_len,
	size_t suffix_len)
	{
	#ifdef GIT_WIN32
	size_t path_chars, total_chars;
	path_chars = git_utf8_char_length(path, path_len);
	if (GIT_ADD_SIZET_OVERFLOW(&total_chars, path_chars, suffix_len) ||
	total_chars > MAX_PATH) {
	git_error_set(GIT_ERROR_FILESYSTEM, "path too long: '%s'", path);
	return -1;
	}
	return 0;
	#else
	GIT_UNUSED(path);
	GIT_UNUSED(path_len);
	GIT_UNUSED(suffix_len);
	return 0;
	#endif
	}

[pde-cds]

@ethomson Any thoughts about this?