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From:   Dwaipayan Ray <dwaipayanray1@gmail.com>
To:     joe@perches.com
Cc:     linux-kernel@vger.kernel.org, lukas.bulwahn@gmail.com,
        Dwaipayan Ray <dwaipayanray1@gmail.com>
Subject: [PATCH v2] checkpatch: fix uninitialized return value in raw_line subroutine
Date:   Sun, 25 Apr 2021 13:14:50 +0530
Message-Id: <20210425074450.6902-1-dwaipayanray1@gmail.com>
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Precedence: bulk

In case the second argument to raw_line subroutine is 0,
$line remains uninitialized and is returned back to the caller.
If the caller then tries to perform string concatenation with
that value, checkpatch throws an error:

Use of uninitialized value in concatenation (.) or string at
./scripts/checkpatch.pl line 1960.

Fix it by providing an empty string as the initial value
for $line.

Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
---

Changes in v2:
- Change commit message

 scripts/checkpatch.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 23697a6b1eaa..a98217360375 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1943,7 +1943,7 @@ sub raw_line {
 	my $offset = $linenr - 1;
 	$cnt++;
 
-	my $line;
+	my $line = "";
 	while ($cnt) {
 		$line = $rawlines[$offset++];
 		next if (defined($line) && $line =~ /^-/);
-- 
2.30.0