From 31dcf99e618ac34c42b40eb5b95e9e1f1af6064e Mon Sep 17 00:00:00 2001
From: Alexei Sorokin <sor.alexei@meowr.ru>
Date: Thu, 23 Jul 2020 18:12:01 +0300
Subject: [PATCH] [DATABASE] Make unprefixed schema.php a bit more DBMS-neutral

---
 lib/database/mysqlschema.php | 32 +++++++++++++++++++++++++
 lib/database/pgsqlschema.php | 45 ------------------------------------
 lib/database/schema.php      | 43 +++++++++++++++++++++++++---------
 3 files changed, 64 insertions(+), 56 deletions(-)

diff --git a/lib/database/mysqlschema.php b/lib/database/mysqlschema.php
index f86abf26b9..4572467937 100644
--- a/lib/database/mysqlschema.php
+++ b/lib/database/mysqlschema.php
@@ -379,6 +379,25 @@ class MysqlSchema extends Schema
         return "{$tableName}_{$columnName}_idx";
     }
 
+    /**
+     * Append phrase(s) to an array of partial ALTER TABLE chunks in order
+     * to alter the given column from its old state to a new one.
+     *
+     * @param array $phrase
+     * @param string $columnName
+     * @param array $old previous column definition as found in DB
+     * @param array $cd current column definition
+     */
+    public function appendAlterModifyColumn(
+        array &$phrase,
+        string $columnName,
+        array  $old,
+        array  $cd
+    ): void {
+        $phrase[] = 'MODIFY COLUMN ' . $this->quoteIdentifier($columnName)
+                  . ' ' . $this->columnSql($columnName, $cd);
+    }
+
     /**
      * MySQL doesn't take 'DROP CONSTRAINT', need to treat primary keys as
      * if they were indexes here, but can use 'PRIMARY KEY' special name.
@@ -427,6 +446,19 @@ class MysqlSchema extends Schema
         }
     }
 
+    /**
+     * Append an SQL statement to drop an index from a table.
+     * Note that in MariaDB index names are relation-specific.
+     *
+     * @param array $statements
+     * @param string $table
+     * @param string $name
+     */
+    public function appendDropIndex(array &$statements, $table, $name)
+    {
+        $statements[] = "DROP INDEX {$name} ON {$this->quoteIdentifier($table)}";
+    }
+
     private function isNumericType(array $cd): bool
     {
         $ints = array_map(
diff --git a/lib/database/pgsqlschema.php b/lib/database/pgsqlschema.php
index c47728865b..046a3bd43d 100644
--- a/lib/database/pgsqlschema.php
+++ b/lib/database/pgsqlschema.php
@@ -316,57 +316,12 @@ class PgsqlSchema extends Schema
         return implode(' ', $line);
     }
 
-    /**
-     * Append phrase(s) to an array of partial ALTER TABLE chunks in order
-     * to alter the given column from its old state to a new one.
-     *
-     * @param array $phrase
-     * @param string $columnName
-     * @param array $old previous column definition as found in DB
-     * @param array $cd current column definition
-     */
-    public function appendAlterModifyColumn(array &$phrase, $columnName, array $old, array $cd)
-    {
-        $prefix = 'ALTER COLUMN ' . $this->quoteIdentifier($columnName) . ' ';
-
-        $oldType = $this->typeAndSize($columnName, $old);
-        $newType = $this->typeAndSize($columnName, $cd);
-        if ($oldType != $newType) {
-            $phrase[] = $prefix . 'TYPE ' . $newType;
-        }
-
-        if (!empty($old['not null']) && empty($cd['not null'])) {
-            $phrase[] = $prefix . 'DROP NOT NULL';
-        } elseif (empty($old['not null']) && !empty($cd['not null'])) {
-            $phrase[] = $prefix . 'SET NOT NULL';
-        }
-
-        if (isset($old['default']) && !isset($cd['default'])) {
-            $phrase[] = $prefix . 'DROP DEFAULT';
-        } elseif (!isset($old['default']) && isset($cd['default'])) {
-            $phrase[] = $prefix . 'SET DEFAULT ' . $this->quoteDefaultValue($cd);
-        }
-    }
-
     public function appendAlterDropPrimary(array &$phrase, string $tableName)
     {
         // name hack -- is this reliable?
         $phrase[] = 'DROP CONSTRAINT ' . $this->quoteIdentifier($tableName . '_pkey');
     }
 
-    /**
-     * Append an SQL statement to drop an index from a table.
-     * Note that in PostgreSQL, index names are DB-unique.
-     *
-     * @param array $statements
-     * @param string $table
-     * @param string $name
-     */
-    public function appendDropIndex(array &$statements, $table, $name)
-    {
-        $statements[] = "DROP INDEX $name";
-    }
-
     public function mapType($column)
     {
         $map = [
diff --git a/lib/database/schema.php b/lib/database/schema.php
index 64d53d2330..2950b54a9b 100644
--- a/lib/database/schema.php
+++ b/lib/database/schema.php
@@ -311,7 +311,7 @@ class Schema
      */
     public function appendDropIndex(array &$statements, $table, $name)
     {
-        $statements[] = "DROP INDEX $name ON " . $this->quoteIdentifier($table);
+        $statements[] = "DROP INDEX {$name}";
     }
 
     public function buildIndexList(array $def)
@@ -406,10 +406,10 @@ class Schema
     {
         global $_PEAR;
 
-        $res = $this->conn->query(
-            'ALTER TABLE ' . $this->quoteIdentifier($table) .
-            ' DROP INDEX ' . $name
-        );
+        $statements = [];
+        $this->appendDropIndex($statements, $table, $name);
+
+        $res = $this->conn->query(implode(";\n", $statements));
 
         if ($_PEAR->isError($res)) {
             PEAR_ErrorToPEAR_Exception($res);
@@ -448,6 +448,7 @@ class Schema
      * Modifies a column in the schema.
      *
      * The name must match an existing column and table.
+     * @fixme Relies on MODIFY COLUMN, which is specific to MariaDB/MySQL
      *
      * @param string $table name of the table
      * @param ColumnDef $columndef new definition of the column.
@@ -724,12 +725,32 @@ class Schema
      * @param array $old previous column definition as found in DB
      * @param array $cd current column definition
      */
-    public function appendAlterModifyColumn(array &$phrase, string $columnName, array $old, array $cd)
-    {
-        $phrase[] = 'MODIFY COLUMN ' .
-            $this->quoteIdentifier($columnName) .
-            ' ' .
-            $this->columnSql($columnName, $cd);
+    public function appendAlterModifyColumn(
+        array &$phrase,
+        string $columnName,
+        array  $old,
+        array  $cd
+    ): void {
+        $prefix = 'ALTER COLUMN ' . $this->quoteIdentifier($columnName);
+
+        // @fixme TYPE is a PostgreSQL extension
+        $oldType = $this->typeAndSize($columnName, $old);
+        $newType = $this->typeAndSize($columnName, $cd);
+        if ($oldType !== $newType) {
+            $phrase[] = $prefix . ' TYPE ' . $newType;
+        }
+
+        if (!($old['not null'] ?? false) && ($cd['not null'] ?? false)) {
+            $phrase[] = $prefix . ' SET NOT NULL';
+        } elseif (($old['not null'] ?? false) && !($cd['not null'] ?? false)) {
+            $phrase[] = $prefix . ' DROP NOT NULL';
+        }
+
+        if (!($old['default'] ?? false) && ($cd['default'] ?? false)) {
+            $phrase[] = $prefix . ' SET DEFAULT ' . $this->quoteDefaultValue($cd);
+        } elseif (($old['default'] ?? false) && !($cd['default'] ?? false)) {
+            $phrase[] = $prefix . ' DROP DEFAULT';
+        }
     }
 
     /**