Only leave space for git diff markers if any line is modified (#3406)

Previously, setting `--style=changes` would always print a 2-space
indent, even if the file was unmodified. This changes the style to only
print an indent if there is at least one +/- git marker in the sidebar.

CHANGELOG.md

@@ -20,6 +20,7 @@
 - Send all bat errors to stderr by default, see #3336 (@JerryImMouse)
 - Make --map-syntax target case insensitive to match --language, see #3206 (@keith-hall)
 - Correctly determine the end of the line in UTF16LE/BE input #3369 (@keith-hall)
+- `--style=changes` no longer prints a two-space indent when the file is unmodified, see issue #2710 and PR #3406 (@jyn514)
 
 ## Other
 

src/printer.rs

@@ -227,7 +227,9 @@ impl<'a> InteractivePrinter<'a> {
 
         #[cfg(feature = "git")]
         {
-            if config.style_components.changes() {
+            if config.style_components.changes()
+                && line_changes.as_ref().is_some_and(|c| !c.is_empty())
+            {
                 decorations.push(Box::new(LineChangesDecoration::new(&colors)));
             }
         }

tests/integration_tests.rs

@@ -1854,11 +1854,11 @@ fn header_default() {
         .success()
         .stdout(
             "\
-───────┬────────────────────────────────────────────────────────────────────────
+─────┬──────────────────────────────────────────────────────────────────────────
-       │ File: single-line.txt
+     │ File: single-line.txt
-───────┼────────────────────────────────────────────────────────────────────────
+─────┼──────────────────────────────────────────────────────────────────────────
-   1   │ Single Line
+   1 │ Single Line
-───────┴────────────────────────────────────────────────────────────────────────
+─────┴──────────────────────────────────────────────────────────────────────────
 ",
         )
         .stderr("");
@@ -1878,16 +1878,31 @@ fn header_default_is_default() {
         .success()
         .stdout(
             "\
-───────┬────────────────────────────────────────────────────────────────────────
+─────┬──────────────────────────────────────────────────────────────────────────
-       │ File: single-line.txt
+     │ File: single-line.txt
-───────┼────────────────────────────────────────────────────────────────────────
+─────┼──────────────────────────────────────────────────────────────────────────
-   1   │ Single Line
+   1 │ Single Line
-───────┴────────────────────────────────────────────────────────────────────────
+─────┴──────────────────────────────────────────────────────────────────────────
 ",
         )
         .stderr("");
 }
 
+#[test]
+#[cfg(feature = "git")] // Expected output assumes git is enabled
+                        // Make sure indent isn't printed if there's no changes
+fn header_and_changes_only() {
+    bat()
+        .arg("--style=header-filename,changes")
+        .arg("--decorations=always")
+        .arg("--color=never")
+        .arg("single-line.txt")
+        .assert()
+        .success()
+        .stdout("File: single-line.txt\nSingle Line\n")
+        .stderr("");
+}
+
 #[test]
 fn filename_stdin() {
     bat()
@@ -2282,12 +2297,12 @@ fn grid_for_file_without_newline() {
         .success()
         .stdout(
             "\
-───────┬────────────────────────────────────────────────────────────────────────
+─────┬──────────────────────────────────────────────────────────────────────────
-       │ File: single-line.txt
+     │ File: single-line.txt
-       │ Size: 11 B
+     │ Size: 11 B
-───────┼────────────────────────────────────────────────────────────────────────
+─────┼──────────────────────────────────────────────────────────────────────────
-   1   │ Single Line
+   1 │ Single Line
-───────┴────────────────────────────────────────────────────────────────────────
+─────┴──────────────────────────────────────────────────────────────────────────
 ",
         )
         .stderr("");