Fix NXM handler for AppImage: use stable executable path

The NXM handler wrapper script was using
QCoreApplication::applicationFilePath() which returns the temporary
FUSE mount path for AppImages (/tmp/.mount_FluoriXXXXXX/...).  This
path changes every launch and doesn't exist when the AppImage isn't
running, breaking NXM downloads from Nexus.

Now uses the APPIMAGE env var (the actual .AppImage file path on disk)
which is stable across launches and always accessible.

Fixes #20

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/src/src/nxmhandler_linux.cpp b/src/src/nxmhandler_linux.cpp
index 1203585..3e18658 100644
--- a/src/src/nxmhandler_linux.cpp
+++ b/src/src/nxmhandler_linux.cpp
@@ -196,7 +196,16 @@ void NxmHandlerLinux::registerHandler() const
   }
 
   const QString wrapperPath = localBin + "/mo2-nxm-handler";
-  const QString executable  = QCoreApplication::applicationFilePath();
+
+  // Determine a stable executable path for the wrapper script.
+  // QCoreApplication::applicationFilePath() returns the temp FUSE mount for
+  // AppImages (/tmp/.mount_XXXXX/...) which changes every launch.  Use the
+  // APPIMAGE env var (the actual .AppImage file) when available.
+  QString executable = qEnvironmentVariable("APPIMAGE");
+  if (executable.isEmpty()) {
+    executable = QCoreApplication::applicationFilePath();
+  }
+
   const QString wrapper =
       QString("#!/bin/sh\nexec \"%1\" nxm-handle \"$@\"\n").arg(executable);