Revert git blame handling (#746)

* Security bug:
time-rs/time#293
https://rustsec.org/advisories/RUSTSEC-2020-0159.html
https://github.com/dandavison/delta/runs/4003260368?check_suite_focus=true

* No fix available in the chrono crate:
https://github.com/chronotope/chrono/issues/602

4 files changed, 0 insertions, 188 deletions

diff --git a/src/delta.rs b/src/delta.rs
index 92d8691f..cab9d6fb 100644
--- a/src/delta.rs
+++ b/src/delta.rs
@@ -22,7 +22,6 @@ pub enum State {
     HunkPlus(Option<String>), // In hunk; added line (raw_line)
     SubmoduleLog, // In a submodule section, with gitconfig diff.submodule = log
     SubmoduleShort(String), // In a submodule section, with gitconfig diff.submodule = short
-    Blame(String), // In a line of `git blame` output.
     Unknown,
     // The following elements are created when a line is wrapped to display it:
     HunkZeroWrapped,  // Wrapped unchanged line
@@ -120,7 +119,6 @@ impl<'a> StateMachine<'a> {
                 || self.handle_submodule_log_line()?
                 || self.handle_submodule_short_line()?
                 || self.handle_hunk_line()?
-                || self.handle_blame_line()?
                 || self.should_skip_line()
                 || self.emit_line_unchanged()?;
         }
diff --git a/src/handlers/blame.rs b/src/handlers/blame.rs
deleted file mode 100644
index 5cbeaa2c..00000000
--- a/src/handlers/blame.rs
+++ /dev/null
@@ -1,183 +0,0 @@
-use chrono::{DateTime, FixedOffset};
-use lazy_static::lazy_static;
-use regex::Regex;
-
-use crate::color;
-use crate::config;
-use crate::delta::{self, State, StateMachine};
-use crate::format::{self, Placeholder};
-use crate::paint::BgShouldFill;
-use crate::style::Style;
-
-impl<'a> StateMachine<'a> {
-    /// If this is a line of git blame output then render it accordingly. If
-    /// this is the first blame line, then set the syntax-highlighter language
-    /// according to delta.default-language.
-    pub fn handle_blame_line(&mut self) -> std::io::Result<bool> {
-        let mut handled_line = false;
-        self.painter.emit()?;
-        if matches!(self.state, State::Unknown | State::Blame(_)) {
-            if let Some(blame) =
-                parse_git_blame_line(&self.line, &self.config.blame_timestamp_format)
-            {
-                // Determine color for this line
-                let color = if let Some(color) = self.blame_commit_colors.get(blame.commit) {
-                    color
-                } else {
-                    let n_commits = self.blame_commit_colors.len();
-                    let n_colors = self.config.blame_palette.len();
-                    let new_color = &self.config.blame_palette[(n_commits + 1) % n_colors];
-                    self.blame_commit_colors
-                        .insert(blame.commit.to_owned(), new_color.to_owned());
-                    new_color
-                };
-                let mut style = Style::from_colors(None, color::parse_color(color, true));
-                style.is_syntax_highlighted = true;
-
-                // Construct commit metadata, paint, and emit
-                let format_data = format::parse_line_number_format(
-                    &self.config.blame_format,
-                    &*BLAME_PLACEHOLDER_REGEX,
-                    false,
-                );
-                write!(
-                    self.painter.writer,
-                    "{}",
-                    style.paint(format_blame_metadata(&format_data, &blame, self.config))
-                )?;
-
-                // Emit syntax-highlighted code
-                if matches!(self.state, State::Unknown) {
-                    if let Some(lang) = self.config.default_language.as_ref() {
-                        self.painter.set_syntax(Some(lang));
-                        self.painter.set_highlighter();
-                    }
-                    self.state = State::Blame(blame.commit.to_owned());
-                }
-                self.painter.syntax_highlight_and_paint_line(
-                    blame.code,
-                    style,
-                    self.state.clone(),
-                    BgShouldFill::default(),
-                );
-                handled_line = true
-            }
-        }
-        Ok(handled_line)
-    }
-}
-
-#[derive(Debug)]
-pub struct BlameLine<'a> {
-    pub commit: &'a str,
-    pub author: &'a str,
-    pub time: DateTime<FixedOffset>,
-    pub line_number: usize,
-    pub code: &'a str,
-}
-
-// E.g.
-//ea82f2d0 (Dan Davison       2021-08-22 18:20:19 -0700 120)             let mut handled_line = self.handle_commit_meta_header_line()?
-
-lazy_static! {
-    static ref BLAME_LINE_REGEX: Regex = Regex::new(
-        r"(?x)
-^
-(
-    [0-9a-f]{8}    # commit hash
-)
-[\ ]
-\(                 # open (
-(
-    [^\ ].*[^\ ]   # author name
-)
-[\ ]+
-(                  # timestamp
-    [0-9]{4}-[0-9]{2}-[0-9]{2}\ [0-9]{2}:[0-9]{2}:[0-9]{2}\ [-+][0-9]{4}
-)
-[\ ]+
-(
-    [0-9]+        # line number
-)
-\)                # close )
-(
-    .*            # code, with leading space
-)
-$
-"
-    )
-    .unwrap();
-}
-
-pub fn parse_git_blame_line<'a>(line: &'a str, timestamp_format: &str) -> Option<BlameLine<'a>> {
-    let caps = BLAME_LINE_REGEX.captures(line)?;
-
-    let commit = caps.get(1).unwrap().as_str();
-    let author = caps.get(2).unwrap().as_str();
-    let timestamp = caps.get(3).unwrap().as_str();
-
-    let time = DateTime::parse_from_str(timestamp, timestamp_format).ok()?;
-
-    let line_number = caps.get(4).unwrap().as_str().parse::<usize>().ok()?;
-
-    let code = caps.get(5).unwrap().as_str();
-
-    Some(BlameLine {
-        commit,
-        author,
-        time,
-        line_number,
-        code,
-    })
-}
-
-lazy_static! {
-    pub static ref BLAME_PLACEHOLDER_REGEX: Regex =
-        format::make_placeholder_regex(&["timestamp", "author", "commit"]);
-}
-
-pub fn format_blame_metadata(
-    format_data: &[format::FormatStringPlaceholderData],
-    blame: &BlameLine,
-    config: &config::Config,
-) -> String {
-    let mut s = String::new();
-    let mut suffix = "";
-    for placeholder in format_data {
-        s.push_str(placeholder.prefix.as_str());
-
-        let alignment_spec = placeholder
-            .alignment_spec
-            .as_ref()
-            .unwrap_or(&format::Align::Left);
-        let width = placeholder.width.unwrap_or(15);
-
-        let pad = |s| format::pad(s, width, alignment_spec);
-        match placeholder.placeholder {
-            Some(Placeholder::Str("timestamp")) => s.push_str(&pad(
-                &chrono_humanize::HumanTime::from(blame.time).to_string(),
-            )),
-            Some(Placeholder::Str("author")) => s.push_str(&pad(blame.author)),
-            Some(Placeholder::Str("commit")) => {
-                s.push_str(&pad(&delta::format_raw_line(blame.commit, config)))
-            }
-            None => {}
-            _ => unreachable!("Unexpected `git blame` input"),
-        }
-        suffix = placeholder.suffix.as_str();
-    }
-    s.push_str(suffix);
-    s
-}
-
-#[test]
-fn test_blame_line_regex() {
-    for line in &[
-        "ea82f2d0 (Dan Davison       2021-08-22 18:20:19 -0700 120)             let mut handled_line = self.handle_commit_meta_header_line()?",
-        "b2257cfa (Dan Davison  2020-07-18 15:34:43 -0400   1) use std::borrow::Cow;"
-    ] {
-        let caps = BLAME_LINE_REGEX.captures(line);
-        assert!(caps.is_some());
-        assert!(parse_git_blame_line(line, "%Y-%m-%d %H:%M:%S %z").is_some());
-    }
-}
diff --git a/src/handlers/mod.rs b/src/handlers/mod.rs
index db27e28f..6302c739 100644
--- a/src/handlers/mod.rs
+++ b/src/handlers/mod.rs
@@ -1,6 +1,5 @@
 /// This module contains functions handling input lines encountered during the
 /// main `StateMachine::consume()` loop.
-pub mod blame;
 pub mod commit_meta;
 pub mod diff_stat;
 pub mod draw;
diff --git a/src/paint.rs b/src/paint.rs
index 3dd4ae4a..bcf3e941 100644
--- a/src/paint.rs
+++ b/src/paint.rs
@@ -468,7 +468,6 @@ impl<'a> Painter<'a> {
                     (config.plus_style, config.plus_non_emph_style)
                 }
             }
-            State::Blame(_) => (diff_sections[0].0, diff_sections[0].0),
             _ => (config.null_style, config.null_style),
         };
         let fill_style = if style_sections_contain_more_than_one_style(diff_sections) {
@@ -622,7 +621,6 @@ impl<'a> Painter<'a> {
             }
             State::HunkHeader(_, _) => true,
             State::HunkMinus(Some(_)) | State::HunkPlus(Some(_)) => false,
-            State::Blame(_) => true,
             _ => panic!(
                 "should_compute_syntax_highlighting is undefined for state {:?}",
                 state