From b9a8047099d2388c15e6ad39e7b8c91c6633096c Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Fri, 9 Feb 2024 01:06:49 -0800
Subject: =?UTF-8?q?grep:=20fix=20=E2=80=98grep=20-m2=20pattern=20<file=20>?=
 =?UTF-8?q?/dev/null=E2=80=99?=
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Problem reported by Grisha Levit <https://bugs.gnu.org/68989>.
* src/grep.c (grep, main): Don’t set done_on_match if -m is used.
* tests/max-count-overread: Add a test case.
---
 src/grep.c               | 9 +++++++--
 tests/max-count-overread | 6 ++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/grep.c b/src/grep.c
index dab3be7..1256dfd 100644
--- a/src/grep.c
+++ b/src/grep.c
@@ -1558,7 +1558,11 @@ grep (int fd, struct stat const *st, bool *ineof)
           if (binary_files == WITHOUT_MATCH_BINARY_FILES)
             return 0;
           if (!count_matches)
-            done_on_match = out_quiet = true;
+            {
+              out_quiet = true;
+              if (max_count == INTMAX_MAX)
+                done_on_match = true;
+            }
           nlines_first_null = nlines;
           nul_zapper = eol;
           skip_nuls = skip_empty_lines;
@@ -2897,7 +2901,8 @@ main (int argc, char **argv)
   if ((exit_on_match | dev_null_output) || list_files != LISTFILES_NONE)
     {
       count_matches = false;
-      done_on_match = true;
+      if (max_count == INTMAX_MAX)
+        done_on_match = true;
     }
   out_quiet = count_matches | done_on_match;
 
diff --git a/tests/max-count-overread b/tests/max-count-overread
index 23c45cb..f829cc5 100755
--- a/tests/max-count-overread
+++ b/tests/max-count-overread
@@ -12,4 +12,10 @@ echo x > exp || framework_failure_
 yes x | timeout 10 grep -m1 x > out || fail=1
 compare exp out || fail=1
 
+# Make sure -m2 stops reading even when output is /dev/null.
+# In grep 3.11, it would continue reading.
+printf 'x\nx\nx\n' >in || framework_failure
+(grep -m2 x >/dev/null && head -n1) <in >out || fail=1
+compare exp out || fail=1
+
 Exit $fail
-- 
cgit v1.1

