FIX Use empty array as a fallback for preg_split within DBText summary

src/ORM/FieldType/DBText.php

@@ -80,7 +80,7 @@ public function LimitSentences($maxSentences = 2)
         }
 
         // Do a word-search
-        $words = preg_split('/\s+/u', $value);
+        $words = preg_split('/\s+/u', $value) ?: [];
         $sentences = 0;
         foreach ($words as $i => $word) {
             if (preg_match('/(!|\?|\.)$/', $word) && !preg_match('/(Dr|Mr|Mrs|Ms|Miss|Sr|Jr|No)\.$/i', $word)) {
@@ -133,8 +133,8 @@ public function Summary($maxWords = 50, $add = false)
         // Split on sentences (don't remove period)
         $sentences = array_filter(array_map(function ($str) {
             return trim($str);
-        }, preg_split('@(?<=\.)@', $value)));
-        $wordCount = count(preg_split('#\s+#u', $sentences[0]));
+        }, preg_split('@(?<=\.)@', $value) ?: []));
+        $wordCount = count(preg_split('#\s+#u', $sentences[0]) ?: []);
 
         // if the first sentence is too long, show only the first $maxWords words
         if ($wordCount > $maxWords) {
@@ -149,7 +149,7 @@ public function Summary($maxWords = 50, $add = false)
 
             // If more sentences to process, count number of words
             if ($sentences) {
-                $wordCount += count(preg_split('#\s+#u', $sentences[0]));
+                $wordCount += count(preg_split('#\s+#u', $sentences[0]) ?: []);
             }
         } while ($wordCount < $maxWords && $sentences && trim($sentences[0]));
 
@@ -169,7 +169,7 @@ public function FirstParagraph()
         }
 
         // Split paragraphs and return first
-        $paragraphs = preg_split('#\n{2,}#', $value);
+        $paragraphs = preg_split('#\n{2,}#', $value) ?: [];
         return reset($paragraphs);
     }
 

tests/php/ORM/DBTextTest.php

@@ -114,7 +114,7 @@ public function providerLimitWordCount()
             ['The little brown fox jumped over the lazy cow.', 3, 'The little brown…'],
             [' This text has white space around the ends ', 3, 'This text has…'],
 
-            // Words less than the limt word count don't get truncated, ellipsis not added
+            // Words less than the limit word count don't get truncated, ellipsis not added
             ['Two words', 3, 'Two words'],  // Two words shouldn't have an ellipsis
             ['These three words', 3, 'These three words'], // Three words shouldn't have an ellipsis
             ['One', 3, 'One'],  // Neither should one word
@@ -216,7 +216,7 @@ public function testFirstSentence($originalValue, $expectedValue)
     }
 
     /**
-     * each test is in the format input, charactere limit, highlight, expected output
+     * each test is in the format input, character limit, highlight, expected output
      *
      * @return array
      */
@@ -268,18 +268,53 @@ public function providerContextSummary()
                 'both schön and können have umlauts',
                 21,
                 '',
-                // check non existant search term
+                // check non-existent search term
                 'both schön and können…',
             ]
+        ];
+    }
 
-
+    /**
+     * each test is in the format input, word limit, add ellipsis (false or string), expected output
+     *
+     * @return array
+     */
+    public function providerSummary()
+    {
+        return [
+            [
+                'This is some text. It is a test',
+                3,
+                false,
+                'This is some…',
+            ],
+            [
+                // check custom ellipsis
+                'This is a test text in a longer sentence and a custom ellipsis.',
+                8,
+                '...', // regular dots instead of the ellipsis character
+                'This is a test text in a longer...',
+            ],
+            [
+                'both schön and können have umlauts',
+                5,
+                false,
+                'both schön and können have…',
+            ],
+            [
+                // check invalid UTF8 handling — input is an invalid UTF sequence, output should be empty string
+                "\xf0\x28\x8c\xbc",
+                50,
+                false,
+                '',
+            ],
         ];
     }
 
     /**
      * @dataProvider providerContextSummary
      * @param string $originalValue Input
-     * @param int    $limit         Numer of characters
+     * @param int    $limit         Number of characters
      * @param string $keywords      Keywords to highlight
      * @param string $expectedValue Expected output (XML encoded safely)
      */
@@ -352,4 +387,18 @@ public function testDefaultEllipsis()
         $textObj = new DBText('Test');
         $this->assertEquals('…', $textObj->defaultEllipsis());
     }
+
+    /**
+     * @dataProvider providerSummary
+     * @param string $originalValue Input
+     * @param int    $words         Number of words
+     * @param mixed  $add           Ellipsis (false for default or string for custom text)
+     * @param string $expectedValue Expected output (XML encoded safely)
+     */
+    public function testSummary($originalValue, $words, $add, $expectedValue)
+    {
+        $text = DBField::create_field(DBText::class, $originalValue);
+        $result = $text->obj('Summary', [$words, $add])->forTemplate();
+        $this->assertEquals($expectedValue, $result);
+    }
 }