[PATCH] send-email: fix uninitialized var warning for $smtp_auth

On the latest version of git-send-email, I see this error just before
running SMTP auth (I didn't provide any --smtp-auth= parameter):

  Use of uninitialized value $smtp_auth in pattern match (m//) at /usr/local/google/home/briannorris/git/git/git-send-email.perl line 1139.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Jan Viktorin <redacted>
Cc: Eric Sunshine <redacted>
Cc: Junio C Hamano <redacted>
---
 git-send-email.perl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index c5a3f766f7fd..e3ff44b4d0cd 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl

@@ -1136,7 +1136,7 @@ sub smtp_auth_maybe {
 
 	# Check mechanism naming as defined in:
 	# https://tools.ietf.org/html/rfc4422#page-8
-	if ($smtp_auth !~ /^(\b[A-Z0-9-_]{1,20}\s*)*$/) {
+	if ($smtp_auth && $smtp_auth !~ /^(\b[A-Z0-9-_]{1,20}\s*)*$/) {
 		die "invalid smtp auth: '${smtp_auth}'";
 	}
 

-- 
2.6.0.rc0.131.gf624c3d

On Fri, Sep 18, 2015 at 03:12:50PM -0700, Brian Norris wrote:

Thanks, makes sense. I wonder if moving the check to the point where
$smtp_auth is actually used (despite the noisier diff) would be cleaner,
like this:

--- 8< ---
diff --git a/git-send-email.perl b/git-send-email.perl
index c5a3f76..2a5ceda 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl

@@ -1134,12 +1134,6 @@ sub smtp_auth_maybe {
 		Authen::SASL->import(qw(Perl));
 	};
 
-	# Check mechanism naming as defined in:
-	# https://tools.ietf.org/html/rfc4422#page-8
-	if ($smtp_auth !~ /^(\b[A-Z0-9-_]{1,20}\s*)*$/) {
-		die "invalid smtp auth: '${smtp_auth}'";
-	}
-
 	# TODO: Authentication may fail not because credentials were
 	# invalid but due to other reasons, in which we should not
 	# reject credentials.

@@ -1154,6 +1148,12 @@ sub smtp_auth_maybe {
 		my $cred = shift;
 
 		if ($smtp_auth) {
+			# Check mechanism naming as defined in:
+			# https://tools.ietf.org/html/rfc4422#page-8
+			if ($smtp_auth !~ /^(\b[A-Z0-9-_]{1,20}\s*)*$/) {
+				die "invalid smtp auth: '${smtp_auth}'";
+			}
+
 			my $sasl = Authen::SASL->new(
 				mechanism => $smtp_auth,
 				callback => {
--- 8< ---

On Fri, Sep 18, 2015 at 06:25:24PM -0400, Eric Sunshine wrote:

By moving the patch into the sub-subroutine (is this a lambda? I'm not
too familiar with my perl), I think you change the order of the checks.
So, previously, initial password auth would happen after the
$smtp_auth format check. With your patch, it comes first.

My patch:

  $ git send-email --smtp-auth="@" ...
  ...
  Send this email? ([y]es|[n]o|[q]uit|[a]ll): y
  invalid smtp auth: '@' at ./git-send-email.perl line 1140.

Your patch:

  $ git send-email --smtp-auth="@" ...
  ...
  Send this email? ([y]es|[n]o|[q]uit|[a]ll): y
  Password for xxxx:
  invalid smtp auth: '@' at ./git-send-email.perl line 1155.

Seems like the former is a little better, so you don't have to waste
time with your password too many times.

Regards,
Brian

On Fri, Sep 18, 2015 at 6:42 PM, Brian Norris
[off-list ref] wrote:

On Fri, Sep 18, 2015 at 06:25:24PM -0400, Eric Sunshine wrote:

quoted

Thanks, makes sense. I wonder if moving the check to the point where
$smtp_auth is actually used (despite the noisier diff) would be cleaner,

By moving the patch into the sub-subroutine (is this a lambda? I'm not
too familiar with my perl), I think you change the order of the checks.
So, previously, initial password auth would happen after the
$smtp_auth format check. With your patch, it comes first.

My patch:

  $ git send-email --smtp-auth="@" ...
  ...
  Send this email? ([y]es|[n]o|[q]uit|[a]ll): y
  invalid smtp auth: '@' at ./git-send-email.perl line 1140.

Your patch:

  $ git send-email --smtp-auth="@" ...
  ...
  Send this email? ([y]es|[n]o|[q]uit|[a]ll): y
  Password for xxxx:
  invalid smtp auth: '@' at ./git-send-email.perl line 1155.

Seems like the former is a little better, so you don't have to waste
time with your password too many times.

Makes sense (again). Thanks for the explanation.

On Fri, Sep 18, 2015 at 06:47:20PM -0400, Eric Sunshine wrote:

Makes sense (again). Thanks for the explanation.

No problem. Thanks for the review.