Use git2::DiffLineType enum instead of char values (extrawurst#655)

The DiffLineType enum in asyncgit has fewer variants: it maps context lines and
line types we don't expect to None. This behavior is kept unchanged.

Now calls `.origin_value()` rather than `.origin()` except in one debug log.

asyncgit/src/sync/diff.rs

@@ -27,6 +27,19 @@ pub enum DiffLineType {
     Delete,
 }
 
+impl From<git2::DiffLineType> for DiffLineType {
+    fn from(line_type: git2::DiffLineType) -> Self {
+        match line_type {
+            git2::DiffLineType::HunkHeader => Self::Header,
+            git2::DiffLineType::DeleteEOFNL
+            | git2::DiffLineType::Deletion => Self::Delete,
+            git2::DiffLineType::AddEOFNL
+            | git2::DiffLineType::Addition => Self::Add,
+            _ => Self::None,
+        }
+    }
+}
+
 impl Default for DiffLineType {
     fn default() -> Self {
         Self::None
@@ -237,18 +250,11 @@ fn raw_diff_to_file_diff<'a>(
                     }
                 }
 
-                let line_type = match line.origin() {
-                    'H' => DiffLineType::Header,
-                    '<' | '-' => DiffLineType::Delete,
-                    '>' | '+' => DiffLineType::Add,
-                    _ => DiffLineType::None,
-                };
-
                 let diff_line = DiffLine {
                     position: DiffLinePosition::from(&line),
                     content: String::from_utf8_lossy(line.content())
                         .to_string(),
-                    line_type,
+                    line_type: line.origin_value().into(),
                 };
 
                 current_lines.push(diff_line);

asyncgit/src/sync/staging/mod.rs

@@ -8,7 +8,7 @@ use super::{
     diff::DiffLinePosition, patches::HunkLines, utils::work_dir,
 };
 use crate::error::Result;
-use git2::{DiffLine, Repository};
+use git2::{DiffLine, DiffLineType, Repository};
 use std::{
     collections::HashSet, convert::TryFrom, fs::File, io::Read,
 };
@@ -82,8 +82,16 @@ pub(crate) fn apply_selection(
     let mut new_content = NewFromOldContent::default();
     let lines = lines.iter().collect::<HashSet<_>>();
 
-    let char_added = if reverse { '-' } else { '+' };
-    let char_deleted = if reverse { '+' } else { '-' };
+    let added = if reverse {
+        DiffLineType::Deletion
+    } else {
+        DiffLineType::Addition
+    };
+    let deleted = if reverse {
+        DiffLineType::Addition
+    } else {
+        DiffLineType::Deletion
+    };
 
     let mut first_hunk_encountered = false;
     for hunk in hunks {
@@ -122,36 +130,38 @@ pub(crate) fn apply_selection(
                         .trim()
                 );
 
-                if hunk_line.origin() == '<'
-                    || hunk_line.origin() == '>'
+                if hunk_line.origin_value()
+                    == DiffLineType::DeleteEOFNL
+                    || hunk_line.origin_value()
+                        == DiffLineType::AddEOFNL
                 {
                     break;
                 }
 
                 if (is_staged && !selected_line)
                     || (!is_staged && selected_line)
                 {
-                    if hunk_line.origin() == char_added {
+                    if hunk_line.origin_value() == added {
                         new_content.add_from_hunk(hunk_line)?;
                         if is_staged {
                             new_content.skip_old_line();
                         }
-                    } else if hunk_line.origin() == char_deleted {
+                    } else if hunk_line.origin_value() == deleted {
                         if !is_staged {
                             new_content.skip_old_line();
                         }
                     } else {
                         new_content.add_old_line(old_lines);
                     }
                 } else {
-                    if hunk_line.origin() != char_added {
+                    if hunk_line.origin_value() != added {
                         new_content.add_from_hunk(hunk_line)?;
                     }
 
                     if (is_staged
-                        && hunk_line.origin() != char_deleted)
+                        && hunk_line.origin_value() != deleted)
                         || (!is_staged
-                            && hunk_line.origin() != char_added)
+                            && hunk_line.origin_value() != added)
                     {
                         new_content.skip_old_line();
                     }