From 253b93be3378fa7750e0c4a08fc8736f984e5b95 Mon Sep 17 00:00:00 2001
From: Mohsen Zainalpour <zainalpour@gmail.com>
Date: Mon, 22 Jun 2026 19:24:29 -0400
Subject: [PATCH] grep: detect format flags inside clustered short options

has_format_flag only matched exact tokens like "-l", but
extract_pattern_path merges boolean short flags into one cluster
(e.g. `-rln` becomes `-ln` after stripping `r`). A bundled -l/-c/-o/-L/-Z
never matched, so grep_cmd tried to NUL-parse rg's output as if it were
normal match lines, even though -l/-c/etc. change rg's output shape
entirely. The result was a false "0 matches" instead of the real answer.

Now has_format_flag also scans the individual letters of a short-flag
cluster, so a bundled format flag correctly falls through to the
existing passthrough path.
---
 src/cmds/system/grep_cmd.rs | 38 ++++++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)

diff --git a/src/cmds/system/grep_cmd.rs b/src/cmds/system/grep_cmd.rs
index b3954526a..e392c618c 100644
--- a/src/cmds/system/grep_cmd.rs
+++ b/src/cmds/system/grep_cmd.rs
@@ -500,8 +500,9 @@ fn parse_match_line(line: &str) -> Option<(String, usize, &str)> {
 
 fn has_format_flag<T: AsRef<str>>(extra_args: &[T]) -> bool {
     extra_args.iter().any(|arg| {
-        matches!(
-            arg.as_ref(),
+        let s = arg.as_ref();
+        if matches!(
+            s,
             "-c" | "--count"
                 | "--count-matches"
                 | "-l"
@@ -515,7 +516,20 @@ fn has_format_flag<T: AsRef<str>>(extra_args: &[T]) -> bool {
                 | "--json"
                 | "--passthru"
                 | "--files"
-        )
+        ) {
+            return true;
+        }
+        // extract_pattern_path merges boolean short flags into one cluster
+        // token (e.g. `-rln` becomes `-ln` after stripping `r`), so a format
+        // flag like `-l` can arrive bundled with others rather than as its
+        // own arg. Clusters only ever contain boolean letters (see
+        // parse_cluster), so scanning characters here is safe.
+        if let Some(rest) = s.strip_prefix('-') {
+            if !rest.is_empty() && !rest.starts_with('-') {
+                return rest.chars().any(|c| matches!(c, 'c' | 'l' | 'L' | 'o' | 'Z'));
+            }
+        }
+        false
     })
 }
 
@@ -1119,6 +1133,24 @@ mod tests {
         assert!(!has_format_flag(&["-i", "-w", "-A", "3"]));
     }
 
+    #[test]
+    fn test_format_flag_detects_clustered_l() {
+        // `-rln` becomes `-ln` after extract_pattern_path strips the `r`.
+        // -l (files-with-matches) is bundled with -n here, not standalone.
+        assert!(has_format_flag(&["-ln"]));
+    }
+
+    #[test]
+    fn test_format_flag_detects_clustered_c() {
+        assert!(has_format_flag(&["-ic"]));
+    }
+
+    #[test]
+    fn test_format_flag_ignores_double_dash() {
+        // Long flags must not be mistaken for a short cluster.
+        assert!(!has_format_flag(&["--ignore-case"]));
+    }
+
     // Verify line numbers are always enabled in rg invocation (grep_cmd.rs:24).
     // The -n/--line-numbers clap flag in main.rs is a no-op accepted for compat.
     #[test]