The name 'tls' is misleading. The 'ssl' option enables a generic
"modern" encryption stack which might very well use TLS; but the 'tls'
option enables STARTTLS support, which works entirely differently.

This renames the canonical option to 'starttls', to make this
distinction more obvious, and adds 'tls' as an alias for starttls, to
avoid breaking config files.

Signed-off-by: Drew DeVault <redacted>
---
 Documentation/git-send-email.txt |  6 ++++--
 git-send-email.perl              | 10 +++++++---
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/Documentation/git-send-email.txt b/Documentation/git-send-email.txt
index 520b355e50..f8cea9e1f9 100644
--- a/Documentation/git-send-email.txt
+++ b/Documentation/git-send-email.txt

@@ -168,12 +168,14 @@ Sending
 	unspecified, choosing the envelope sender is left to your MTA.
 
 --smtp-encryption=<encryption>::
-	Specify the encryption to use, either 'ssl' or 'tls'. 'ssl' enables
-	generic SSL/TLS support and is typically used on port 465.  'tls'
+	Specify the encryption to use, either 'ssl' or 'starttls'. 'ssl' enables
+	generic SSL/TLS support and is typically used on port 465.  'starttls'
 	enables in-band STARTTLS support and is typically used on port 25 or
 	587.  Use whichever option is recommended by your mail provider.  Leave
 	empty to disable encryption and use plain SMTP.  Default is the value of
 	`sendemail.smtpEncryption`.
++
+'tls' is an alias for 'starttls' for legacy reasons.
 
 --smtp-domain=<FQDN>::
 	Specifies the Fully Qualified Domain Name (FQDN) used in the

diff --git a/git-send-email.perl b/git-send-email.perl
index bda5211f0d..3f125bc2b8 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl

@@ -495,8 +495,12 @@ sub read_config {
 
 # 'default' encryption is none -- this only prevents a warning
 $smtp_encryption = '' unless (defined $smtp_encryption);
-if ($smtp_encryption ne "" && $smtp_encryption ne "ssl" && $smtp_encryption ne "tls") {
-	die __("Invalid smtp_encryption configuration: expected 'ssl', 'tls', or nothing.\n");
+if ($smtp_encryption eq "tls") {
+	# "tls" is an alias for starttls for legacy reasons
+	$smtp_encryption = "starttls";
+};

+if ($smtp_encryption ne "" && $smtp_encryption ne "ssl" && $smtp_encryption ne "starttls") {
+	die __("Invalid smtp_encryption configuration: expected 'ssl', 'starttls', or nothing.\n");
 }
 
 # Set CC suppressions

@@ -1541,7 +1545,7 @@ sub send_message {
 						 Hello => $smtp_domain,
 						 Debug => $debug_net_smtp,
 						 Port => $smtp_server_port);
-			if ($smtp_encryption eq 'tls' && $smtp) {
+			if ($smtp_encryption eq 'starttls' && $smtp) {