From 9535eaa8a8dcdaa60f4c6c6d0523ab9c890a6a7e Mon Sep 17 00:00:00 2001
From: Michael Sharp <michael.sharp@platform.sh>
Date: Wed, 26 Aug 2020 12:51:20 +1000
Subject: [PATCH 1/2] Add a host block header only if adding more lines

This way, if no lines are added, the config file doesn't end with a host
block header.
---
 src/Service/SshConfig.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/Service/SshConfig.php b/src/Service/SshConfig.php
index d01e52407..670864354 100644
--- a/src/Service/SshConfig.php
+++ b/src/Service/SshConfig.php
@@ -71,12 +71,15 @@ public function configureSessionSsh()
             $lines[] = '';
         }
 
+
+        $hostBlock = '';
         if ($domainWildcards) {
-            $lines[] = 'Host ' . implode(' ', $domainWildcards);
+            $hostBlock = 'Host ' . implode(' ', $domainWildcards);
         }
 
         $sessionIdentityFile = $this->sshKey->selectIdentity();
         if ($sessionIdentityFile !== null) {
+            $lines[] = $hostBlock;
             $lines[] = '# This SSH key was detected as corresponding to the session:';
             $lines[] = sprintf('IdentityFile %s', $sessionIdentityFile);
             $lines[] = '';
@@ -95,6 +98,7 @@ public function configureSessionSsh()
         if ($sessionIdentityFile === null && ($defaultFiles = $this->getUserDefaultSshIdentityFiles())) {
             $lines[] = '# Include SSH "default" identity files:';
             foreach ($defaultFiles as $identityFile) {
+                $lines[] = $hostBlock;
                 $lines[] = sprintf('IdentityFile %s', $identityFile);
             }
             $lines[] = '';

From cd5d307c41ff07e2a144943096b5fd7639684bca Mon Sep 17 00:00:00 2001
From: Michael Sharp <michael.sharp@platform.sh>
Date: Wed, 26 Aug 2020 12:52:10 +1000
Subject: [PATCH 2/2] Move the no-lines-added test to the end

Wait until we've added all the lines we're going to before we decide to
remove the files.

Previously, this would never happen because we unconditionally added a
host block header to the lines - so in practice, this never caused any
strange behaviour.
---
 src/Service/SshConfig.php | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/Service/SshConfig.php b/src/Service/SshConfig.php
index 670864354..e8489b322 100644
--- a/src/Service/SshConfig.php
+++ b/src/Service/SshConfig.php
@@ -85,15 +85,6 @@ public function configureSessionSsh()
             $lines[] = '';
         }
 
-        $sessionSpecificFilename = $this->getSessionSshDir() . DIRECTORY_SEPARATOR . 'config';
-        $includerFilename = $this->getCliSshDir() . DIRECTORY_SEPARATOR . 'session.config';
-        if (empty($lines)) {
-            if (\file_exists($includerFilename) || \file_exists($sessionSpecificFilename)) {
-                $this->fs->remove([$includerFilename, $sessionSpecificFilename]);
-            }
-            return false;
-        }
-
         // Add default files if there is no preferred session identity file.
         if ($sessionIdentityFile === null && ($defaultFiles = $this->getUserDefaultSshIdentityFiles())) {
             $lines[] = '# Include SSH "default" identity files:';
@@ -104,6 +95,15 @@ public function configureSessionSsh()
             $lines[] = '';
         }
 
+        $sessionSpecificFilename = $this->getSessionSshDir() . DIRECTORY_SEPARATOR . 'config';
+        $includerFilename = $this->getCliSshDir() . DIRECTORY_SEPARATOR . 'session.config';
+        if (empty($lines)) {
+            if (\file_exists($includerFilename) || \file_exists($sessionSpecificFilename)) {
+                $this->fs->remove([$includerFilename, $sessionSpecificFilename]);
+            }
+            return false;
+        }
+
         $this->writeSshIncludeFile($sessionSpecificFilename, $lines);
 
         $includerLines = [