From 2ab686ee714eb9c171d841489d67a976a9f05338 Mon Sep 17 00:00:00 2001
From: Eloy Lafuente <stronk7@moodle.org>
Date: Sun, 21 Mar 2010 19:36:50 +0000
Subject: [PATCH] MDL-21868 mssql generator - improve integer meta type
 detection + test

---
 lib/ddl/mssql_sql_generator.php | 22 ++++++++++++++++++++++
 lib/ddl/simpletest/testddl.php  | 13 +++++++++++--
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/lib/ddl/mssql_sql_generator.php b/lib/ddl/mssql_sql_generator.php
index 4dfdaa93e02..57ee52bde80 100644
--- a/lib/ddl/mssql_sql_generator.php
+++ b/lib/ddl/mssql_sql_generator.php
@@ -321,6 +321,28 @@ class mssql_sql_generator extends sql_generator {
             $typechanged = false;
         }
 
+    /// If the new field (and old) specs are for integer, let's be a bit more specific diferentiating
+    /// types of integers. Else, some combinations can cause things like MDL-21868
+        if ($xmldb_field->getType() == XMLDB_TYPE_INTEGER && $oldmetatype == 'I') {
+            if ($xmldb_field->getLength() > 9) { // Convert our new lenghts to detailed meta types
+                $newmssqlinttype = 'I8';
+            } else if ($xmldb_field->getLength() > 4) {
+                $newmssqlinttype = 'I';
+            } else {
+                $newmssqlinttype = 'I2';
+            }
+            if ($metac->type == 'bigint') { // Convert current DB type to detailed meta type (our metatype is not enough!)
+                $oldmssqlinttype = 'I8';
+            } else if ($metac->type == 'smallint') {
+                $oldmssqlinttype = 'I2';
+            } else {
+                $oldmssqlinttype = 'I';
+            }
+            if ($newmssqlinttype != $oldmssqlinttype) { // Compare new and old meta types
+                $typechanged = true; // Change in meta type means change in type at all effects
+            }
+        }
+
     /// Detect if we are changing the length of the column, not always necessary to drop defaults
     /// if only the length changes, but it's safe to do it always
         if ($xmldb_field->getLength() == $oldlength) {
diff --git a/lib/ddl/simpletest/testddl.php b/lib/ddl/simpletest/testddl.php
index d4b7500e64f..ae9d6da126b 100755
--- a/lib/ddl/simpletest/testddl.php
+++ b/lib/ddl/simpletest/testddl.php
@@ -815,14 +815,23 @@ class ddl_test extends UnitTestCase {
         $this->assertEqual($columns['grade']->meta_type, 'N');
         //TODO: chek the rest of attributes
 
-        // change integer field from 10 to 6
+        // change integer field from 10 to 2
         $field = new xmldb_field('userid');
-        $field->set_attributes(XMLDB_TYPE_INTEGER, '6', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0');
+        $field->set_attributes(XMLDB_TYPE_INTEGER, '2', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0');
         $dbman->change_field_precision($table, $field);
         $columns = $DB->get_columns('test_table1');
         $this->assertEqual($columns['userid']->meta_type, 'I');
         //TODO: chek the rest of attributes
 
+        // change the column from integer (2) to integer (6) (forces change of type in some DBs)
+        $field = new xmldb_field('userid');
+        $field->set_attributes(XMLDB_TYPE_INTEGER, '6', XMLDB_UNSIGNED, null, null, null);
+        $dbman->change_field_precision($table, $field);
+        // column is integer 6 null default null now
+        $columns = $DB->get_columns('test_table1');
+        $this->assertEqual($columns['userid']->meta_type, 'I');
+        //TODO: chek the rest of attributes
+
         // insert one record with 6-digit field
         $record = new object();
         $record->course = 10;