Fix IMAP mailMove crash on malformed MIME-encoded thread titles

organizer/src/class/Imap/ImapWrapper.php

@@ -271,7 +271,28 @@ function() use ($imap_stream, $msg_number, $options) {
     public function utf8(string $text): string {
         $textPreview = strlen($text) > 50 ? substr($text, 0, 50) . '...' : $text;
         $this->logDebug('utf8', ["text: $textPreview"]);
-        return \imap_utf8($text);
+
+        // Clear any previous errors - imap_errors() returns errors and clears them
+        \imap_errors();
+
+        $result = \imap_utf8($text);
+
+        // Check if there were any new errors (e.g., invalid quoted-printable sequence)
+        // imap_errors() will return errors from imap_utf8() call and clear them
+        $errors = \imap_errors();
+        if ($errors !== false && count($errors) > 0) {
+            // Log the error but don't throw an exception - return the original text
+            // This handles cases where MIME-encoded headers are malformed
+            $errorMsg = implode(', ', $errors);
+            error_log("IMAP utf8 conversion warning for text '$textPreview': $errorMsg");
+            // If imap_utf8 failed, try mb_decode_mimeheader as a fallback
+            if (strpos($text, '=?') !== false) {
+                return mb_decode_mimeheader($text);
+            }
+            return $text;
+        }
+
+        return $result;
     }
 
     public function fetchstructure(mixed $imap_stream, int $msg_number, int $options = 0): object {

organizer/src/class/ThreadFolderManager.php

@@ -69,6 +69,12 @@ public function archiveThreadFolder($entityThreads, $thread): void {
     public static function getThreadEmailFolder($entity_id, $thread): string {
         $title = $entity_id . ' - ' . $thread->title;
 
+        // Decode any MIME-encoded headers (e.g., =?UTF-8?B?...?= or =?iso-8859-1?Q?...?=)
+        // Only decode if the string contains MIME encoding markers to avoid corrupting UTF-8 text
+        if (strpos($title, '=?') !== false) {
+            $title = mb_decode_mimeheader($title);
+        }
+
         // Replace Nordic characters
         $title = str_replace(
             ['Æ', 'Ø', 'Å', 'æ', 'ø', 'å'],

organizer/src/tests/ImapWrapperUtf8Test.php

@@ -0,0 +1,75 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+use Imap\ImapWrapper;
+
+require_once __DIR__ . '/../class/Imap/ImapWrapper.php';
+
+class ImapWrapperUtf8Test extends TestCase
+{
+    public function testUtf8WithNormalText()
+    {
+        $wrapper = new ImapWrapper();
+        $text = 'Normal text';
+        $result = $wrapper->utf8($text);
+
+        $this->assertEquals($text, $result);
+    }
+
+    public function testUtf8WithValidMimeEncodedString()
+    {
+        $wrapper = new ImapWrapper();
+        // Valid MIME-encoded string: "Test Title" in UTF-8 base64
+        $text = '=?UTF-8?B?VGVzdCBUaXRsZQ==?=';
+        $result = $wrapper->utf8($text);
+
+        // imap_utf8() should decode this properly
+        $this->assertEquals('Test Title', $result);
+    }
+
+    public function testUtf8WithMalformedMimeEncodedString()
+    {
+        $wrapper = new ImapWrapper();
+        // Malformed MIME-encoded string from the error report
+        $text = '=?iso-8859-1?Q?axz5ZAFym5luZoxqfgeds8xO/E+PtRicCu3CXJTfFFl7/aub8+5SDA59PR? =?iso-';
+
+        // This should not throw an exception
+        $result = $wrapper->utf8($text);
+
+        // Should return a string (may be the same as input if imap_utf8 can't decode it)
+        $this->assertIsString($result);
+    }
+
+    public function testUtf8WithEmptyString()
+    {
+        $wrapper = new ImapWrapper();
+        $text = '';
+        $result = $wrapper->utf8($text);
+
+        $this->assertEquals('', $result);
+    }
+
+    public function testUtf8WithUtf8Text()
+    {
+        $wrapper = new ImapWrapper();
+        // UTF-8 text with special characters
+        $text = 'Tëst wîth spëcîal çhâracters';
+        $result = $wrapper->utf8($text);
+
+        // Should return the text as-is or decoded
+        $this->assertIsString($result);
+    }
+
+    public function testUtf8WithNordicCharacters()
+    {
+        $wrapper = new ImapWrapper();
+        // Nordic characters
+        $text = 'Æble Øre Åre';
+        $result = $wrapper->utf8($text);
+
+        // Should handle Nordic characters properly
+        $this->assertIsString($result);
+        $this->assertStringContainsString('ble', $result);
+        $this->assertStringContainsString('re', $result);
+    }
+}

organizer/src/tests/ThreadFolderManagerTest.php

@@ -263,4 +263,44 @@ public function testCreateRequiredFoldersWithConcurrentOperations() {
 
         $this->threadFolderManager->createRequiredFolders($threads);
     }
+
+    public function testGetThreadEmailFolderWithMimeEncodedTitle() {
+        $entityThreads = (object)[
+            'entity_id' => 'Test',
+            'threads' => []
+        ];
+
+        // Test with a malformed MIME-encoded string (from the error report)
+        $thread = (object)[
+            'title' => '=?iso-8859-1?Q?axz5ZAFym5luZoxqfgeds8xO/E+PtRicCu3CXJTfFFl7/aub8+5SDA59PR? =?iso-',
+            'archived' => false
+        ];
+
+        $folder = $this->threadFolderManager->getThreadEmailFolder($entityThreads->entity_id, $thread);
+
+        // Verify MIME-encoded strings are decoded and sanitized
+        // The malformed MIME header should be decoded as much as possible
+        $this->assertStringStartsWith('INBOX.Test - ', $folder);
+        // Should not contain MIME encoding markers
+        $this->assertStringNotContainsString('=?', $folder);
+        $this->assertStringNotContainsString('?=', $folder);
+    }
+
+    public function testGetThreadEmailFolderWithValidMimeEncodedTitle() {
+        $entityThreads = (object)[
+            'entity_id' => 'Test',
+            'threads' => []
+        ];
+
+        // Test with a valid MIME-encoded string
+        $thread = (object)[
+            'title' => '=?UTF-8?B?VGVzdCBUaXRsZQ==?=', // "Test Title" in base64
+            'archived' => false
+        ];
+
+        $folder = $this->threadFolderManager->getThreadEmailFolder($entityThreads->entity_id, $thread);
+
+        // Verify MIME-encoded strings are decoded properly
+        $this->assertEquals('INBOX.Test - Test Title', $folder);
+    }
 }