From cb51ea42386e68bc1b0b76d73fd2a4c8d363d68b Mon Sep 17 00:00:00 2001
From: Robin Bygrave <robin.bygrave@gmail.com>
Date: Wed, 18 May 2016 21:04:36 +1200
Subject: [PATCH] #713 - DB Migration - When change is from Not Null to Null
 ... this migration is duplicated in subsequent migration generation

---
 .../ebean/dbmigration/model/MColumn.java      |  7 +++++
 .../ebean/dbmigration/model/MColumnTest.java  | 31 +++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/src/main/java/com/avaje/ebean/dbmigration/model/MColumn.java b/src/main/java/com/avaje/ebean/dbmigration/model/MColumn.java
index 286261ca7..ce150d00d 100644
--- a/src/main/java/com/avaje/ebean/dbmigration/model/MColumn.java
+++ b/src/main/java/com/avaje/ebean/dbmigration/model/MColumn.java
@@ -268,6 +268,10 @@ public class MColumn {
     return val != null && !val.isEmpty();
   }
 
+  private boolean hasValue(Boolean val) {
+    return val != null;
+  }
+
   private AlterColumn getAlterColumn(String tableName, boolean tableWithHistory) {
     if (alterColumn == null) {
       alterColumn = new AlterColumn();
@@ -396,6 +400,9 @@ public class MColumn {
     if (hasValue(alterColumn.getType())) {
       type = alterColumn.getType();
     }
+    if (hasValue(alterColumn.isNotnull())) {
+      notnull = alterColumn.isNotnull();
+    }
     if (hasValue(alterColumn.getDefaultValue())) {
       defaultValue = alterColumn.getDefaultValue();
     }
diff --git a/src/test/java/com/avaje/ebean/dbmigration/model/MColumnTest.java b/src/test/java/com/avaje/ebean/dbmigration/model/MColumnTest.java
index 7793999c7..0bcdf6e5e 100644
--- a/src/test/java/com/avaje/ebean/dbmigration/model/MColumnTest.java
+++ b/src/test/java/com/avaje/ebean/dbmigration/model/MColumnTest.java
@@ -58,6 +58,37 @@ public class MColumnTest {
     assertThat(alterColumn.getDefaultValue()).isNull();
   }
 
+  @Test
+  public void diffNull() throws Exception {
+
+    ModelDiff diff = diff();
+
+    MColumn newCol = basic();
+    newCol.setNotnull(false);
+
+    MColumn baseCol = basic();
+    baseCol.setNotnull(true);
+
+    baseCol.compare(diff, table, newCol);
+
+    assertChanges(diff);
+    AlterColumn alterColumn = getAlterColumn(diff);
+    assertThat(alterColumn.isNotnull()).isEqualTo(false);
+  }
+
+  @Test
+  public void applyNotNull_expect_notNull() throws Exception {
+
+    MColumn newCol = basic();
+    newCol.setNotnull(true);
+
+    AlterColumn alterColumn = new AlterColumn();
+    alterColumn.setNotnull(Boolean.FALSE);
+    newCol.apply(alterColumn);
+
+    assertThat(newCol.isNotnull()).isFalse();
+  }
+
   @Test
   public void diffCheckAdd() throws Exception {