diff options
Diffstat (limited to 'path.c')
| -rw-r--r-- | path.c | 96 |
1 files changed, 68 insertions, 28 deletions
@@ -1290,37 +1290,77 @@ int daemon_avoid_alias(const char *p) } } -static int only_spaces_and_periods(const char *path, size_t len, size_t skip) +/* + * On NTFS, we need to be careful to disallow certain synonyms of the `.git/` + * directory: + * + * - For historical reasons, file names that end in spaces or periods are + * automatically trimmed. Therefore, `.git . . ./` is a valid way to refer + * to `.git/`. + * + * - For other historical reasons, file names that do not conform to the 8.3 + * format (up to eight characters for the basename, three for the file + * extension, certain characters not allowed such as `+`, etc) are associated + * with a so-called "short name", at least on the `C:` drive by default. + * Which means that `git~1/` is a valid way to refer to `.git/`. + * + * Note: Technically, `.git/` could receive the short name `git~2` if the + * short name `git~1` were already used. In Git, however, we guarantee that + * `.git` is the first item in a directory, therefore it will be associated + * with the short name `git~1` (unless short names are disabled). + * + * - For yet other historical reasons, NTFS supports so-called "Alternate Data + * Streams", i.e. metadata associated with a given file, referred to via + * `<filename>:<stream-name>:<stream-type>`. There exists a default stream + * type for directories, allowing `.git/` to be accessed via + * `.git::$INDEX_ALLOCATION/`. + * + * When this function returns 1, it indicates that the specified file/directory + * name refers to a `.git` file or directory, or to any of these synonyms, and + * Git should therefore not track it. + * + * For performance reasons, _all_ Alternate Data Streams of `.git/` are + * forbidden, not just `::$INDEX_ALLOCATION`. + * + * This function is intended to be used by `git fsck` even on platforms where + * the backslash is a regular filename character, therefore it needs to handle + * backlash characters in the provided `name` specially: they are interpreted + * as directory separators. + */ +int is_ntfs_dotgit(const char *name) { - if (len < skip) + char c; + + /* + * Note that when we don't find `.git` or `git~1` we end up with `name` + * advanced partway through the string. That's okay, though, as we + * return immediately in those cases, without looking at `name` any + * further. + */ + c = *(name++); + if (c == '.') { + /* .git */ + if (((c = *(name++)) != 'g' && c != 'G') || + ((c = *(name++)) != 'i' && c != 'I') || + ((c = *(name++)) != 't' && c != 'T')) + return 0; + } else if (c == 'g' || c == 'G') { + /* git ~1 */ + if (((c = *(name++)) != 'i' && c != 'I') || + ((c = *(name++)) != 't' && c != 'T') || + *(name++) != '~' || + *(name++) != '1') + return 0; + } else return 0; - len -= skip; - path += skip; - while (len-- > 0) { - char c = *(path++); - if (c != ' ' && c != '.') + + for (;;) { + c = *(name++); + if (!c || c == '\\' || c == '/' || c == ':') + return 1; + if (c != '.' && c != ' ') return 0; } - return 1; -} - -int is_ntfs_dotgit(const char *name) -{ - size_t len; - - for (len = 0; ; len++) - if (!name[len] || name[len] == '\\' || is_dir_sep(name[len])) { - if (only_spaces_and_periods(name, len, 4) && - !strncasecmp(name, ".git", 4)) - return 1; - if (only_spaces_and_periods(name, len, 5) && - !strncasecmp(name, "git~1", 5)) - return 1; - if (name[len] != '\\') - return 0; - name += len + 1; - len = -1; - } } static int is_ntfs_dot_generic(const char *name, @@ -1336,7 +1376,7 @@ static int is_ntfs_dot_generic(const char *name, only_spaces_and_periods: for (;;) { char c = name[i++]; - if (!c) + if (!c || c == ':') return 1; if (c != ' ' && c != '.') return 0; |