gix_validate/
tag.rs

1use bstr::{BStr, BString, ByteSlice};
2
3///
4pub mod name {
5    use bstr::BString;
6
7    /// The error returned by [`name()`][super::name()].
8    #[derive(Debug)]
9    #[expect(missing_docs)]
10    #[non_exhaustive]
11    pub enum Error {
12        InvalidByte { byte: BString },
13        StartsWithSlash,
14        RepeatedSlash,
15        RepeatedDot,
16        LockFileSuffix,
17        ReflogPortion,
18        Asterisk,
19        StartsWithDot,
20        EndsWithDot,
21        EndsWithSlash,
22        Empty,
23    }
24
25    impl std::fmt::Display for Error {
26        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
27            match self {
28                Error::InvalidByte { byte } => write!(
29                    f,
30                    "A ref must not contain invalid bytes or ascii control characters: {byte:?}"
31                ),
32                Error::StartsWithSlash => write!(f, "A reference name must not start with a slash '/'"),
33                Error::RepeatedSlash => write!(
34                    f,
35                    "Multiple slashes in a row are not allowed as they may change the reference's meaning"
36                ),
37                Error::RepeatedDot => write!(f, "A ref must not contain '..' as it may be mistaken for a range"),
38                Error::LockFileSuffix => write!(f, "A ref must not end with '.lock'"),
39                Error::ReflogPortion => write!(f, "A ref must not contain '@{{' which is a part of a ref-log"),
40                Error::Asterisk => write!(f, "A ref must not contain '*' character"),
41                Error::StartsWithDot => write!(f, "A ref must not start with a '.'"),
42                Error::EndsWithDot => write!(f, "A ref must not end with a '.'"),
43                Error::EndsWithSlash => write!(f, "A ref must not end with a '/'"),
44                Error::Empty => write!(f, "A ref must not be empty"),
45            }
46        }
47    }
48
49    impl std::error::Error for Error {}
50}
51
52/// Assure the given `input` resemble a valid git tag name, which is returned unchanged on success.
53/// Tag names are provided as names, like `v1.0` or `alpha-1`, without paths.
54pub fn name(input: &BStr) -> Result<&BStr, name::Error> {
55    match name_inner(input, Mode::Validate)? {
56        None => Ok(input),
57        Some(_) => {
58            unreachable!("When validating, the input isn't changed")
59        }
60    }
61}
62
63#[derive(Eq, PartialEq)]
64pub(crate) enum Mode {
65    Sanitize,
66    Validate,
67}
68
69/// Validate or sanitize `input` according to `mode`.
70///
71/// Validation returns `Ok(None)` when `input` is valid, while sanitization returns the rebuilt name
72/// in `Ok(Some(_))` even if it is identical to `input`. An error means validation failed.
73pub(crate) fn name_inner(input: &BStr, mode: Mode) -> Result<Option<BString>, name::Error> {
74    let mut out: Option<BString> =
75        matches!(mode, Mode::Sanitize).then(|| BString::from(Vec::with_capacity(input.len())));
76    if input.is_empty() {
77        return if let Some(mut out) = out {
78            out.push(b'-');
79            Ok(Some(out))
80        } else {
81            Err(name::Error::Empty)
82        };
83    }
84    if *input.last().expect("non-empty") == b'/' && out.is_none() {
85        return Err(name::Error::EndsWithSlash);
86    }
87    if input.first() == Some(&b'/') && out.is_none() {
88        return Err(name::Error::StartsWithSlash);
89    }
90
91    let mut previous = 0;
92    let mut component_start;
93    let mut component_end = 0;
94    let last = input.len() - 1;
95    for (byte_pos, byte) in input.iter().enumerate() {
96        match byte {
97            b'\\' | b'^' | b':' | b'[' | b'?' | b' ' | b'~' | b'\0'..=b'\x1F' | b'\x7F' => {
98                if let Some(out) = out.as_mut() {
99                    out.push(b'-');
100                } else {
101                    return Err(name::Error::InvalidByte {
102                        byte: (&[*byte][..]).into(),
103                    });
104                }
105            }
106            b'*' => {
107                if let Some(out) = out.as_mut() {
108                    out.push(b'-');
109                } else {
110                    return Err(name::Error::Asterisk);
111                }
112            }
113
114            b'.' if previous == b'.' => {
115                if out.is_none() {
116                    return Err(name::Error::RepeatedDot);
117                }
118            }
119            b'.' if previous == b'/' => {
120                if let Some(out) = out.as_mut() {
121                    out.push(b'-');
122                } else {
123                    return Err(name::Error::StartsWithDot);
124                }
125            }
126            b'{' if previous == b'@' => {
127                if let Some(out) = out.as_mut() {
128                    out.push(b'-');
129                } else {
130                    return Err(name::Error::ReflogPortion);
131                }
132            }
133            b'/' if previous == b'/' => {
134                if out.is_none() {
135                    return Err(name::Error::RepeatedSlash);
136                }
137            }
138            c => {
139                if *c == b'/' {
140                    component_start = component_end;
141                    component_end = byte_pos;
142
143                    if input[component_start..component_end].ends_with_str(".lock") {
144                        if let Some(out) = out.as_mut() {
145                            while out.ends_with(b".lock") {
146                                let len_without_suffix = out.len() - b".lock".len();
147                                out.truncate(len_without_suffix);
148                            }
149                        } else {
150                            return Err(name::Error::LockFileSuffix);
151                        }
152                    }
153                }
154
155                if let Some(out) = out.as_mut() {
156                    out.push(*c);
157                }
158
159                if byte_pos == last && input[component_end + 1..].ends_with_str(".lock") {
160                    if let Some(out) = out.as_mut() {
161                        while out.ends_with(b".lock") {
162                            let len_without_suffix = out.len() - b".lock".len();
163                            out.truncate(len_without_suffix);
164                        }
165                    } else {
166                        return Err(name::Error::LockFileSuffix);
167                    }
168                }
169            }
170        }
171        previous = *byte;
172    }
173
174    if let Some(out) = out.as_mut() {
175        while out.last() == Some(&b'/') {
176            out.pop();
177        }
178        while out.first() == Some(&b'/') {
179            out.remove(0);
180        }
181    }
182    if out.as_ref().map_or(input, |b| b.as_bstr())[0] == b'.' {
183        if let Some(out) = out.as_mut() {
184            out[0] = b'-';
185        } else {
186            return Err(name::Error::StartsWithDot);
187        }
188    }
189    let last = out.as_ref().map_or(input, |b| b.as_bstr()).len() - 1;
190    if out.as_ref().map_or(input, |b| b.as_bstr())[last] == b'.' {
191        if let Some(out) = out.as_mut() {
192            let last = out.len() - 1;
193            out[last] = b'-';
194        } else {
195            return Err(name::Error::EndsWithDot);
196        }
197    }
198    Ok(out)
199}
gix_validate/tag.rs

gix_validate/
tag.rs
