From: Pádraig Brady <P@draigBrady.com>
Date: Sat, 31 Dec 2022 17:03:39 +0000 (+0000)
Subject: stty: fix off by one column wrapping on output
X-Git-Tag: v9.2~99
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c9a21ec3173b93de4839e5ff9eddadb020431656;p=thirdparty%2Fcoreutils.git

stty: fix off by one column wrapping on output

* src/stty.c (wrapf): Adjust the comparison by 1,
to account for the space we're adding.
* tests/misc/stty.sh: Add a test case.
* NEWS: Mention the fix.
Reported in https://bugs.debian.org/1027442
---

diff --git a/NEWS b/NEWS
index 0beaef5066..6b05c8d35a 100644
--- a/NEWS
+++ b/NEWS
@@ -32,6 +32,10 @@ GNU coreutils NEWS                                    -*- outline -*-
   and the system supported set of valid speeds.
   [This bug was present in "the beginning".]
 
+  stty now wraps output appropriately for the terminal width.
+  Previously it may have output 1 character too wide for certain widths.
+  [bug introduced in coreutils-5.3]
+
   `wc -c` will again efficiently determine the size of large files
   on all systems.  It no longer redundantly reads data from certain
   sized files larger than SIZE_MAX.
diff --git a/src/stty.c b/src/stty.c
index b4c2cbecd6..f3c7915e11 100644
--- a/src/stty.c
+++ b/src/stty.c
@@ -519,7 +519,7 @@ wrapf (char const *message,...)
 
   if (0 < current_col)
     {
-      if (max_col - current_col < buflen)
+      if (max_col - current_col <= buflen)
         {
           putchar ('\n');
           current_col = 0;
diff --git a/tests/misc/stty.sh b/tests/misc/stty.sh
index bcdc80e878..7abcec5af2 100755
--- a/tests/misc/stty.sh
+++ b/tests/misc/stty.sh
@@ -89,4 +89,10 @@ returns_ 1 strace -o log2 -e ioctl stty -blahblah || fail=1
 n_ioctl2=$(wc -l < log2) || framework_failure_
 test "$n_ioctl1" = "$n_ioctl2" || fail=1
 
+# Ensure we wrap output appropriately
+for W in $(seq 80 90); do
+  output_width=$(COLUMNS="$W" stty -a | wc -L)
+  test "$output_width" -le "$W" || fail=1
+done
+
 Exit $fail