Trim double Total output lines (#4787)

codex-rs/core/src/client_common.rs

@@ -159,12 +159,16 @@ fn build_structured_output(parsed: &ExecOutputJson) -> String {
         parsed.metadata.duration_seconds
     ));
 
+    let mut output = parsed.output.clone();
     if let Some(total_lines) = extract_total_output_lines(&parsed.output) {
         sections.push(format!("Total output lines: {total_lines}"));
+        if let Some(stripped) = strip_total_output_header(&output) {
+            output = stripped.to_string();
+        }
     }
 
     sections.push("Output:".to_string());
-    sections.push(parsed.output.clone());
+    sections.push(output);
 
     sections.join("\n")
 }
@@ -177,6 +181,13 @@ fn extract_total_output_lines(output: &str) -> Option<u32> {
     total_segment.parse::<u32>().ok()
 }
 
+fn strip_total_output_header(output: &str) -> Option<&str> {
+    let after_prefix = output.strip_prefix("Total output lines: ")?;
+    let (_, remainder) = after_prefix.split_once('\n')?;
+    let remainder = remainder.strip_prefix('\n').unwrap_or(remainder);
+    Some(remainder)
+}
+
 #[derive(Debug)]
 pub enum ResponseEvent {
     Created,

codex-rs/core/tests/suite/shell_serialization.rs

@@ -255,17 +255,17 @@ async fn shell_output_reserializes_truncated_content() -> Result<()> {
 Wall time: [0-9]+(?:\.[0-9]+)? seconds
 Total output lines: 400
 Output:
-Total output lines: 400
-
 1
 2
 3
 4
 5
 6
-.*\[\.{3} omitted \d+ of 400 lines \.{3}\]
+.*
+\[\.{3} omitted \d+ of 400 lines \.{3}\]
 
-.*\n396
+.*
+396
 397
 398
 399

codex-rs/core/tests/suite/tools.rs

@@ -516,7 +516,6 @@ async fn shell_sandbox_denied_truncates_error_output() -> Result<()> {
 Wall time: [0-9]+(?:\.[0-9]+)? seconds
 Total output lines: \d+
 Output:
-Total output lines: \d+
 
 failed in sandbox: .*?(?:Operation not permitted|Permission denied|Read-only file system).*?
 \[\.{3} omitted \d+ of \d+ lines \.{3}\]
@@ -601,7 +600,6 @@ execution error: .*$"#;
 Wall time: [0-9]+(?:\.[0-9]+)? seconds
 Total output lines: \d+
 Output:
-Total output lines: \d+
 
 execution error: .*$"#;
     let spawn_error_regex = Regex::new(spawn_error_pattern)?;