[11.x] Where doesnt have nullable morph (#54363)

* first pass at allowing querying non existence of nullable morph - will need moving up

* move querying non existence of nullable morph to has morph method

* handle checking for 0 has morphs the same as less than 1 has morphs

* work on assumption that has morph less than needs null check

* attempt to handle all operators

* merge into existing query - all existing tests passing

* add test

* revert signature change

* readd docblocks

* fix space

* formatting

---------

Co-authored-by: Mior Muhammad Zaki <[email protected]>

Author: liamduckett

src/Illuminate/Database/Eloquent/Concerns/QueriesRelationships.php

@@ -244,6 +244,12 @@ public function hasMorph($relation, $types, $operator = '>=', $count = 1, $boole
 
         $types = (array) $types;
 
+        $checkMorphNull = $types === ['*']
+            && (($operator === '<' && $count >= 1)
+                || ($operator === '<=' && $count >= 0)
+                || ($operator === '=' && $count === 0)
+                || ($operator === '!=' && $count >= 1));
+
         if ($types === ['*']) {
             $types = $this->model->newModelQuery()->distinct()->pluck($relation->getMorphType())
                 ->filter()
@@ -274,7 +280,8 @@ public function hasMorph($relation, $types, $operator = '>=', $count = 1, $boole
                         ->whereHas($belongsTo, $callback, $operator, $count);
                 });
             }
-        }, null, null, $boolean);
+        }, null, null, $boolean)
+        ->when($checkMorphNull, fn (self $query) => $query->orWhereMorphedTo($relation, null));
     }
 
     /**

tests/Integration/Database/EloquentWhereHasMorphTest.php

@@ -255,6 +255,13 @@ public function testModelScopesAreAccessible()
 
         $this->assertEquals([1, 4], $comments->pluck('id')->all());
     }
+
+    public function testWhereDoesntHaveMorphWithNullableMorph()
+    {
+        $comments = Comment::whereDoesntHaveMorph('commentable', '*')->orderBy('id')->get();
+
+        $this->assertEquals([3, 7, 8], $comments->pluck('id')->all());
+    }
 }
 
 class Comment extends Model