[12.x] Fix: Make Paginated Queries Consistent Across Pages (#55176)

* Add failing tests

* Make paginated queries more consistent across pages

Author: tomchkk

src/Illuminate/Database/Query/Builder.php

@@ -2790,7 +2790,9 @@ public function forPageBeforeId($perPage = 15, $lastId = 0, $column = 'id')
     {
         $this->orders = $this->removeExistingOrdersFor($column);
 
-        if (! is_null($lastId)) {
+        if (is_null($lastId)) {
+            $this->whereNotNull($column);
+        } else {
             $this->where($column, '<', $lastId);
         }
 
@@ -2810,7 +2812,9 @@ public function forPageAfterId($perPage = 15, $lastId = 0, $column = 'id')
     {
         $this->orders = $this->removeExistingOrdersFor($column);
 
-        if (! is_null($lastId)) {
+        if (is_null($lastId)) {
+            $this->whereNotNull($column);
+        } else {
             $this->where($column, '>', $lastId);
         }
 

tests/Database/DatabaseQueryBuilderTest.php

@@ -2360,6 +2360,28 @@ public function testForPage()
         $this->assertSame('select * from "users" limit 0 offset 0', $builder->toSql());
     }
 
+    public function testForPageBeforeId()
+    {
+        $builder = $this->getBuilder();
+        $builder->select('*')->from('users')->forPageBeforeId(15, null);
+        $this->assertSame('select * from "users" where "id" is not null order by "id" desc limit 15', $builder->toSql());
+
+        $builder = $this->getBuilder();
+        $builder->select('*')->from('users')->forPageBeforeId(15, 0);
+        $this->assertSame('select * from "users" where "id" < ? order by "id" desc limit 15', $builder->toSql());
+    }
+
+    public function testForPageAfterId()
+    {
+        $builder = $this->getBuilder();
+        $builder->select('*')->from('users')->forPageAfterId(15, null);
+        $this->assertSame('select * from "users" where "id" is not null order by "id" asc limit 15', $builder->toSql());
+
+        $builder = $this->getBuilder();
+        $builder->select('*')->from('users')->forPageAfterId(15, 0);
+        $this->assertSame('select * from "users" where "id" > ? order by "id" asc limit 15', $builder->toSql());
+    }
+
     public function testGetCountForPaginationWithBindings()
     {
         $builder = $this->getBuilder();