The argument that a separater should also be output for zero might be
reasonable, because zero is allowed with -A, -B or -C option, though I
think it isn't necessary.
From 722e0a019a1e9c116874e94d249c04109b95f275 Mon Sep 17 00:00:00 2001
From: Norihiro Tanaka <[email protected]>
Date: Sat, 10 May 2014 14:41:57 +0900
Subject: [PATCH] grep: output a separator by explicit zero with -A, -B or -C
option
* src/grep.c (out_before, out_after): Initialize to -1.
(prtext): output a separator if any of them isn't -1.
---
src/grep.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/src/grep.c b/src/grep.c
index 1e3fc28..c402876 100644
--- a/src/grep.c
+++ b/src/grep.c
@@ -667,8 +667,8 @@ static bool out_invert; /* Print nonmatching
stuff. */
static int out_file; /* Print filenames. */
static int out_line; /* Print line numbers. */
static int out_byte; /* Print byte offsets. */
-static intmax_t out_before; /* Lines of leading context. */
-static intmax_t out_after; /* Lines of trailing context. */
+static intmax_t out_before = -1;/* Lines of leading context. */
+static intmax_t out_after = -1; /* Lines of trailing context. */
static int count_matches; /* Count matching lines. */
static int list_files; /* List matching files. */
static int no_filenames; /* Suppress file names. */
@@ -1002,7 +1002,8 @@ prtext (char const *beg, char const *lim)
/* Print the group separator unless the output is adjacent to
the previous output in the file. */
- if ((out_before || out_after) && used && p != lastout && group_separator)
+ if ((out_before >= 0 || out_after >= 0) && used && p != lastout
+ && group_separator)
{
pr_sgr_start_if (sep_color);
fputs (group_separator, stdout);
--
1.9.3
