>From fe41d6c651eb0044e1d152b13f413874ba6bd731 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A1draig=20Brady?= <P@draigBrady.com>
Date: Sun, 25 Oct 2020 16:40:35 +0000
Subject: [PATCH] nl: only fail if need to output overflowed numbers

Previously we would have failed immediately upon internal overflow,
which didn't output the full line being processed, and assumed
there would be another numbered line.

* src/nl.c (line_no_overflow): A new global to track overflow.
(print_lineno): Only fail if about to output an overflowed number.
(reset_lineno): A new function to refactor resetting of the number,
and which also clears line_no_overflow.
* tests/misc/nl.sh: Add a test case.
---
 src/nl.c         | 27 ++++++++++++++++++++-------
 tests/misc/nl.sh | 14 +++++++++++++-
 2 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/src/nl.c b/src/nl.c
index 8fe91f773..154131f36 100644
--- a/src/nl.c
+++ b/src/nl.c
@@ -143,6 +143,9 @@ static char const *lineno_format = FORMAT_RIGHT_NOLZ;
 /* Current print line number.  */
 static intmax_t line_no;
 
+/* Whether the current line number has incremented past limits.  */
+static bool line_no_overflow;
+
 /* True if we have ever read standard input.  */
 static bool have_read_stdin;
 
@@ -275,10 +278,23 @@ build_type_arg (char const **typep,
 static void
 print_lineno (void)
 {
+  if (line_no_overflow)
+    die (EXIT_FAILURE, 0, _("line number overflow"));
+
   printf (lineno_format, lineno_width, line_no, separator_str);
 
   if (INT_ADD_WRAPV (line_no, page_incr, &line_no))
-    die (EXIT_FAILURE, 0, _("line number overflow"));
+    line_no_overflow = true;
+}
+
+static void
+reset_lineno (void)
+{
+  if (reset_numbers)
+    {
+      line_no = starting_line_number;
+      line_no_overflow = false;
+    }
 }
 
 /* Switch to a header section. */
@@ -288,8 +304,7 @@ proc_header (void)
 {
   current_type = header_type;
   current_regex = &header_regex;
-  if (reset_numbers)
-    line_no = starting_line_number;
+  reset_lineno ();
   putchar ('\n');
 }
 
@@ -300,8 +315,7 @@ proc_body (void)
 {
   current_type = body_type;
   current_regex = &body_regex;
-  if (reset_numbers)
-    line_no = starting_line_number;
+  reset_lineno ();
   putchar ('\n');
 }
 
@@ -312,8 +326,7 @@ proc_footer (void)
 {
   current_type = footer_type;
   current_regex = &footer_regex;
-  if (reset_numbers)
-    line_no = starting_line_number;
+  reset_lineno ();
   putchar ('\n');
 }
 
diff --git a/tests/misc/nl.sh b/tests/misc/nl.sh
index 3a9919243..c134a9896 100755
--- a/tests/misc/nl.sh
+++ b/tests/misc/nl.sh
@@ -18,7 +18,7 @@
 
 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
 print_ver_ nl
-
+getlimits_
 
 echo a | nl > out || fail=1
 echo b | nl -s%n >> out || fail=1
@@ -55,4 +55,16 @@ cat <<\EOF > exp
 EOF
 compare exp out || fail=1
 
+# Ensure we only indicate overflow when needing to output overflowed numbers
+returns_ 1 nl -v$INTMAX_OFLOW /dev/null || fail=1
+printf '%s\n' a \\:\\: b > in.txt || framework_failure_
+nl -v$INTMAX_MAX in.txt > out || fail=1
+cat <<EOF > exp
+$INTMAX_MAX	a
+
+$INTMAX_MAX	b
+EOF
+compare exp out || fail=1
+returns_ 1 nl -p -v$INTMAX_MAX in.txt > out || fail=1
+
 Exit $fail
-- 
2.26.2