[PATCH v2] checkpatch: fix missing whitespace in formatted email

[Dwaipayan Ray <dwaipayanray1@gmail.com>]

Commit 0c01921e56f9 ("checkpatch: add new warnings to author signoff
checks.") introduced new checks for author sign off. The format_email
procedure was modified to add comment blocks to the formatted email. But
no space was added between the email address and mail comment.

This causes wrong email formatting in cases where the email is in the form
"author@example.com (Comment block)". The space between the address and
comment block is removed, which causes incorrect parsing of the
formatted email.

An evaluation on checkpatch brought up this case. For example,
on commit 1129d31b55d5 ("ima: Fix ima digest hash table key calculation"),
the following warning was reported:

WARNING:BAD_SIGN_OFF: email address 'David.Laight@aculab.com (big endian
system concerns)' might be better as 'David.Laight@aculab.com(big endian
system concerns)'

Add a single space in between the address and comment when the
extracted comment is not empty.

Fixes: 0c01921e56f9 ("checkpatch: add new warnings to author signoff checks.")
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
---
 scripts/checkpatch.pl | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index fab38b493cef..f1a4e61917eb 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1221,7 +1221,9 @@ sub format_email {
 	} else {
 		$formatted_email = "$name$name_comment <$address>";
 	}
-	$formatted_email .= "$comment";
+	if ("$comment" ne "") {
+		$formatted_email .= " $comment";
+	}
 	return $formatted_email;
 }
 
-- 
2.27.0