bug #858 Fixing missing blank line at end of modified patch files (weaverryan)

This PR was merged into the 1.x branch.

Discussion
----------

Fixing missing blank line at end of modified patch files

Fixes #856

tl;dr If a file has been modified in a recipe, but that file has been deleted in the user's project, we manually remove that file from that patch to avoid conflicts (and we report the patch to the user). There was a bug in that process that didn't guarantee an empty line at the end of the patch file. That made the patch file invalid for git.

Thank you `@fbourigault` for the excellent bug report and reproducer!

Commits
-------

65c7e8e Fixing missing blank line at end of modified patch files

Author: nicolas-grekas

src/Update/DiffHelper.php

@@ -35,6 +35,11 @@ public static function removeFilesFromPatch(string $patch, array $files, array &
             $patch = $contentBefore.substr($patch, $end);
         }
 
+        // valid patches end with a blank line
+        if ($patch && "\n" !== substr($patch, \strlen($patch) - 1, 1)) {
+            $patch = $patch."\n";
+        }
+
         return $patch;
     }
 }

tests/Update/DiffHelperTest.php

@@ -105,6 +105,7 @@ public function getRemoveFilesFromPatchTests(): iterable
 +    dbal:
 +        # "TEST_TOKEN" is typically set by ParaTest
 +        dbname_suffix: '_test%env(default::TEST_TOKEN)%'
+
 EOF
             , [
                 '.env' => <<<EOF
@@ -154,6 +155,7 @@ public function getRemoveFilesFromPatchTests(): iterable
 +    dbal:
 +        # "TEST_TOKEN" is typically set by ParaTest
 +        dbname_suffix: '_test%env(default::TEST_TOKEN)%'
+
 EOF
             , [
                 'config/packages/doctrine.yaml' => <<<EOF
@@ -204,6 +206,7 @@ public function getRemoveFilesFromPatchTests(): iterable
 -            type: pool
 -            pool: doctrine.system_cache_pool
          query_cache_driver:
+
 EOF
             , [
                 'config/packages/test/doctrine.yaml' => <<<EOF
@@ -244,6 +247,7 @@ public function getRemoveFilesFromPatchTests(): iterable
 -            type: pool
 -            pool: doctrine.system_cache_pool
          query_cache_driver:
+
 EOF
             , [
                 'config/packages/test/doctrine.yaml' => <<<EOF