Delete installation directory only if empty

Original source: https://nsis.sourceforge.io/Delete_dir_only_if_empty

Sandboxie/install/SandboxieVS.nsi

@@ -849,10 +849,10 @@ Function CheckUpdates
 DoCheck:
   DetailPrint "Running UpdUtil ..."
   SetDetailsPrint listonly
-  
+
   ExecWait '"$INSTDIR\UpdUtil.exe" $0 sandboxie /step:scan /scope:meta /version:${VERSION}' $1
 	;MessageBox MB_OK "UpdUtil: $0"
-	
+
   IntCmp $1 0 is0 lessthan0 morethan0
   is0:
     ;DetailPrint "no update"
@@ -863,12 +863,12 @@ DoCheck:
   morethan0:
     DetailPrint "$$0 > 5"
     Goto Update
-    
+
 Update:
   MessageBox MB_YESNO|MB_ICONQUESTION "$(MSG_8055)" IDNO NoUpdate
-  
+
   ExecWait '"$INSTDIR\UpdUtil.exe" $0 sandboxie /step:apply /scope:meta'
-    
+
 NoUpdate:
   SetDetailsPrint both
 FunctionEnd
@@ -1150,6 +1150,27 @@ SkipCopyInstaller:
 
 FunctionEnd
 
+;----------------------------------------------------------------------------
+; Function DeleteDirIfEmpty
+;----------------------------------------------------------------------------
+
+Function DeleteDirIfEmpty
+
+  FindFirst $R0 $R1 "$0\*.*"
+  strcmp $R1 "." 0 NoDelete
+   FindNext $R0 $R1
+   strcmp $R1 ".." 0 NoDelete
+    ClearErrors
+    FindNext $R0 $R1
+    IfErrors 0 NoDelete
+     FindClose $R0
+     Sleep 1000
+     RMDir "$0"
+  NoDelete:
+   FindClose $R0
+
+FunctionEnd
+
 ;----------------------------------------------------------------------------
 ; Function DeleteProgramFiles
 ;----------------------------------------------------------------------------
@@ -1183,7 +1204,7 @@ Function DeleteProgramFiles
 
     Delete "$INSTDIR\KmdUtil.exe"
     Delete "$INSTDIR\UpdUtil.exe"
-    
+
     Delete "$INSTDIR\SboxHostDll.dll"
 
     Delete "$INSTDIR\boxHostDll.dll"
@@ -1250,10 +1271,11 @@ Function DeleteProgramFiles
 SkipDeleteSandboxieIni:
 
 ;
-; Delete installation folder
+; Delete installation folder if empty
 ;
 
-    RMDir "$INSTDIR"
+    StrCpy $0 "$INSTDIR"
+    Call DeleteDirIfEmpty
 
 FunctionEnd