Merge pull request #22653 from nextcloud/backport/22643/stable18

[stable18] Fix installing on Oracle

Author: MorrisJobke

core/Migrations/Version18000Date20190920085628.php

@@ -59,7 +59,9 @@ public function changeSchema(IOutput $output, Closure $schemaClosure, array $opt
 			$table->addColumn('displayname', Type::STRING, [
 				'notnull' => true,
 				'length' => 255,
-				'default' => '',
+				// Will be overwritten in postSchemaChange, but Oracle can not save
+				// empty strings in notnull columns
+				'default' => 'name',
 			]);
 		}
 

lib/private/DB/MigrationService.php

@@ -513,6 +513,11 @@ public function ensureOracleIdentifierLengthLimit(Schema $sourceSchema, Schema $
 				if ((!$sourceTable instanceof Table || !$sourceTable->hasColumn($thing->getName())) && \strlen($thing->getName()) > 30) {
 					throw new \InvalidArgumentException('Column name "'  . $table->getName() . '"."' . $thing->getName() . '" is too long.');
 				}
+
+				if ($thing->getNotnull() && $thing->getDefault() === ''
+					&& $sourceTable instanceof Table && !$sourceTable->hasColumn($thing->getName())) {
+					throw new \InvalidArgumentException('Column name "'  . $table->getName() . '"."' . $thing->getName() . '" is NotNull, but has empty string or null as default.');
+				}
 			}
 
 			foreach ($table->getIndexes() as $thing) {