Fix git show rev:path output formatting and duplication

src/git.rs

@@ -135,7 +135,11 @@ fn run_show(args: &[String], max_lines: Option<usize>, verbose: u8) -> Result<()
         .iter()
         .any(|arg| arg.starts_with("--pretty") || arg.starts_with("--format"));
 
-    if wants_stat_only || wants_format {
+    // `git show rev:path` prints a blob, not a commit diff. In this mode we should
+    // pass through directly to avoid duplicated output from compact-show steps.
+    let wants_blob_show = args.iter().any(|arg| is_blob_show_arg(arg));
+
+    if wants_stat_only || wants_format || wants_blob_show {
         let mut cmd = Command::new("git");
         cmd.arg("show");
         for arg in args {
@@ -148,7 +152,11 @@ fn run_show(args: &[String], max_lines: Option<usize>, verbose: u8) -> Result<()
             std::process::exit(output.status.code().unwrap_or(1));
         }
         let stdout = String::from_utf8_lossy(&output.stdout);
-        println!("{}", stdout.trim());
+        if wants_blob_show {
+            print!("{}", stdout);
+        } else {
+            println!("{}", stdout.trim());
+        }
 
         timer.track(
             &format!("git show {}", args.join(" ")),
@@ -229,6 +237,11 @@ fn run_show(args: &[String], max_lines: Option<usize>, verbose: u8) -> Result<()
     Ok(())
 }
 
+fn is_blob_show_arg(arg: &str) -> bool {
+    // Detect `rev:path` style arguments while ignoring flags like `--pretty=format:...`.
+    !arg.starts_with('-') && arg.contains(':')
+}
+
 pub(crate) fn compact_diff(diff: &str, max_lines: usize) -> String {
     let mut result = Vec::new();
     let mut current_file = String::new();
@@ -1342,6 +1355,15 @@ mod tests {
         assert!(result.contains("+"));
     }
 
+    #[test]
+    fn test_is_blob_show_arg() {
+        assert!(is_blob_show_arg("develop:modules/pairs_backtest.py"));
+        assert!(is_blob_show_arg("HEAD:src/main.rs"));
+        assert!(!is_blob_show_arg("--pretty=format:%h"));
+        assert!(!is_blob_show_arg("--format=short"));
+        assert!(!is_blob_show_arg("HEAD"));
+    }
+
     #[test]
     fn test_filter_branch_output() {
         let output = "* main\n  feature/auth\n  fix/bug-123\n  remotes/origin/HEAD -> origin/main\n  remotes/origin/main\n  remotes/origin/feature/auth\n  remotes/origin/release/v2\n";