hc: implement Restart Houdini and add to menu/panel

 MainMenuCommon.xml             |  8 ++++----
 python3.11libs/hc/hcmaps.py    |  1 +
 python3.11libs/hc/hcsession.py | 34 ++++++++++++++++++++++++++--------
 3 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/MainMenuCommon.xml b/MainMenuCommon.xml
index ed6d01d..b4e81f3 100755
--- a/MainMenuCommon.xml
+++ b/MainMenuCommon.xml
@@ -76,10 +76,10 @@
         <scriptCode><![CDATA[from hc import HCSession; HCSession().toggleAllTabs()]]></scriptCode>
       </scriptItem>
 
-      <!-- <scriptItem id="h.hc_session_restarthoudini"> -->
-        <!-- <label>Restart Houdini</label> -->
-        <!-- <scriptCode><![CDATA[from hc import HCSession; HCSession().restartHoudini()]]></scriptCode> -->
-      <!-- </scriptItem> -->
+      <scriptItem id="h.hc_session_restarthoudini">
+        <label>Restart Houdini</label>
+        <scriptCode><![CDATA[from hc import HCSession; HCSession().restartHoudini()]]></scriptCode>
+      </scriptItem>
 
       <scriptItem id="h.hc_session_togglemenus">
         <label>Toggle Menus</label>
diff --git a/python3.11libs/hc/hcmaps.py b/python3.11libs/hc/hcmaps.py
index 65294c7..40c56ae 100644
--- a/python3.11libs/hc/hcmaps.py
+++ b/python3.11libs/hc/hcmaps.py
@@ -21,6 +21,7 @@ class HCMaps:
             'Reload HC':                 session.reloadHC,
             'Reload Hotkeys':            session.reloadHotkeys,
             'Reload Keycam':             session.reloadKeycam,
+            'Restart Houdini':           session.restartHoudini,
             # 'Rename Tabs':               session.renameTabs,
             'Save':                      session.save,
             'Set Type: NetworkEditor':   lambda: self.tab.setType('NetworkEditor'),
diff --git a/python3.11libs/hc/hcsession.py b/python3.11libs/hc/hcsession.py
index c61f890..acdb197 100644
--- a/python3.11libs/hc/hcsession.py
+++ b/python3.11libs/hc/hcsession.py
@@ -271,14 +271,32 @@ class HCSession:
         for callback in callbacks:
             hou.ui.removeEventLoopCallback(callback)
 
-    # def restartHoudini(self):
-        # import os
-        # import subprocess
-        # executable = sys.argv[0]
-        # executable = os.environ.get("HFS") + "/bin/houdini"
-        # subprocess.Popen([executable])
-        # hou.exit()
-        # return
+    def restartHoudini(self):
+        import os
+        import subprocess
+        import sys
+        
+        # Save current state so 123.py knows what to open if we don't pass it explicitly,
+        # but we will pass it explicitly to be safe.
+        current_hip = hou.hipFile.path()
+        if not hou.hipFile.isUntitled():
+            hou.hipFile.save()
+        
+        # Get the path to the houdini executable
+        # On Linux, this is usually in $HFS/bin/houdini
+        hfs = os.environ.get("HFS")
+        if hfs:
+            executable = os.path.join(hfs, "bin", "houdini")
+        else:
+            executable = "houdini" # Fallback to path
+
+        # Launch new process
+        # We pass the current hip file as an argument so it opens directly
+        args = [executable, current_hip]
+        subprocess.Popen(args, close_fds=True)
+        
+        # Exit current instance
+        hou.exit()
 
     def save(self):
         hou.hipFile.save()