Check returned Bundle ID for NULL

PR #19463.

src/base/preferences.cpp

@@ -1411,6 +1411,7 @@ bool Preferences::isTorrentFileAssocSet()
         if (defaultHandlerId != NULL)
         {
             const CFStringRef myBundleId = CFBundleGetIdentifier(CFBundleGetMainBundle());
+            if (myBundleId != NULL)
                 isSet = CFStringCompare(myBundleId, defaultHandlerId, 0) == kCFCompareEqualTo;
             CFRelease(defaultHandlerId);
         }
@@ -1423,10 +1424,12 @@ void Preferences::setTorrentFileAssoc()
 {
     if (isTorrentFileAssocSet())
         return;
+
     const CFStringRef torrentId = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, torrentExtension, NULL);
     if (torrentId != NULL)
     {
         const CFStringRef myBundleId = CFBundleGetIdentifier(CFBundleGetMainBundle());
+        if (myBundleId != NULL)
             LSSetDefaultRoleHandlerForContentType(torrentId, kLSRolesViewer, myBundleId);
         CFRelease(torrentId);
     }
@@ -1439,6 +1442,7 @@ bool Preferences::isMagnetLinkAssocSet()
     if (defaultHandlerId != NULL)
     {
         const CFStringRef myBundleId = CFBundleGetIdentifier(CFBundleGetMainBundle());
+        if (myBundleId != NULL)
             isSet = CFStringCompare(myBundleId, defaultHandlerId, 0) == kCFCompareEqualTo;
         CFRelease(defaultHandlerId);
     }
@@ -1449,7 +1453,9 @@ void Preferences::setMagnetLinkAssoc()
 {
     if (isMagnetLinkAssocSet())
         return;
+
     const CFStringRef myBundleId = CFBundleGetIdentifier(CFBundleGetMainBundle());
+    if (myBundleId != NULL)
         LSSetDefaultHandlerForURLScheme(magnetUrlScheme, myBundleId);
 }
 #endif // Q_OS_MACOS