'git checkout' fails if a directory is longer than PATH_MAX, because the
lstat_cache in symlinks.c checks if the leading directory exists using
PATH_MAX-bounded string operations.

Remove the limitation by using strbuf instead.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Rename cache_def_free to cache_def_clear as it doesn't free the struct
cache_def, but just clears its content.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Karsten Blees <blees@dcon.de>

There is no actual nested struct here. Move it out for clarity.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Karsten Blees <blees@dcon.de>

This also fixes the problem of silently ignoring .gitignore if the
full path exceeds PATH_MAX. Now add_excludes_from_file() will report
if it gets ENAMETOOLONG.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Karsten Blees <blees@dcon.de>

Use a suffciently large buffer to strip the trailing slash.

Signed-off-by: Karsten Blees <blees@dcon.de>

…ries

Win32: fix checkout problem with directories exceeding MAX_PATH