Highlighting when middle line hasn't changed that much

[walles]

In the following test case, the middle line should have &mut actual_result and file.reopen().unwrap() highlighted on the middle changed line, and nothing else.

I think highlighting fully changed lines has no value, that's why the first and last lines should not be highlighted.

git show af2c3de7840bf6307b34076eb4db782e3fcb0c42 src/main.rs | tail -13

@@ -442,9 +438,9 @@ mod tests {
             println!("Evaluating example file <{}>...", diff.to_str().unwrap());

             // Run highlighting on the file into a memory buffer
-            let mut actual_result: Vec<u8> = Vec::new();
-            highlight_diff(&mut fs::File::open(diff).unwrap(), &mut actual_result);
-            let actual_result = str::from_utf8(&actual_result).unwrap();
+            let file = tempfile::NamedTempFile::new().unwrap();
+            highlight_diff(&mut fs::File::open(diff).unwrap(), file.reopen().unwrap());
+            let actual_result = fs::read_to_string(file.path()).unwrap();

             // Load the corresponding .riff-output file into a string
             let basename = diff.file_stem().unwrap().to_str().unwrap();

[walles]

Fixed in release 2.13.