native: fix uninstall self-destruction behavior...... by not showing the command prompt window and fork-spawning the cmd

src/native/interop.cpp

@@ -8,6 +8,7 @@
 #include "objbase.h"
 #include "objidl.h"
 #include "shlguid.h"
+#include "shlobj.h"
 
 // https://stackoverflow.com/questions/52101827/windows-10-getsyscolor-does-not-get-dark-ui-color-theme
 extern "C" int isDarkThemeActive() {
@@ -32,7 +33,8 @@ extern "C" int saveShortcut(
     const char *description,
     const char *path,
     const char *args,
-    const char *workingDir) {
+    const char *workingDir)
+{
     char *errStr = NULL;
     HRESULT h;
     IShellLink *shellLink = NULL;
@@ -48,20 +50,23 @@ extern "C" int saveShortcut(
 
     // Initialize the COM library
     h = CoInitialize(NULL);
-    if (FAILED(h)) {
+    if (FAILED(h))
+    {
         errStr = "Failed to initialize COM library";
         goto err;
     }
 
     h = CoCreateInstance(CLSID_ShellLink, NULL, CLSCTX_INPROC_SERVER,
                          IID_IShellLink, (PVOID *)&shellLink);
-    if (FAILED(h)) {
+    if (FAILED(h))
+    {
         errStr = "Failed to create IShellLink";
         goto err;
     }
 
     h = shellLink->QueryInterface(IID_IPersistFile, (PVOID *)&persistFile);
-    if (FAILED(h)) {
+    if (FAILED(h))
+    {
         errStr = "Failed to get IPersistFile";
         goto err;
     }
@@ -85,7 +90,8 @@ extern "C" int saveShortcut(
 
     //Save the shortcut to disk
     h = persistFile->Save(wName, TRUE);
-    if (FAILED(h)) {
+    if (FAILED(h))
+    {
         errStr = "Failed to save shortcut";
         goto err;
     }
@@ -105,3 +111,46 @@ err:
     return h;
 }
 
+// NOTE: app and cmdline cannot be constant when Unicode support is enabled
+extern "C" int spawnDetached(const char *app, const char *cmdline)
+{
+    // TODO: Unicode support
+    STARTUPINFOA si;
+    PROCESS_INFORMATION pi;
+
+    ZeroMemory(&si, sizeof(si));
+    si.cb = sizeof(si);
+    ZeroMemory(&pi, sizeof(pi));
+
+    if (!CreateProcessA(app,              // No module name (use command line)
+                        (LPSTR)cmdline,   // Command line, no unicode allowed
+                        NULL,             // Process handle not inheritable
+                        NULL,             // Thread handle not inheritable
+                        FALSE,            // Set handle inheritance to FALSE
+                        CREATE_NO_WINDOW, // Create without window
+                        NULL,             // Use parent's environment block
+                        NULL,             // Use parent's starting directory
+                        &si,              // Pointer to STARTUPINFO structure
+                        &pi)              // Pointer to PROCESS_INFORMATION structure
+    )
+    {
+        return GetLastError();
+    }
+
+    // Close process and thread handles.
+    CloseHandle(pi.hProcess);
+    CloseHandle(pi.hThread);
+    return 0;
+}
+
+extern "C" HRESULT getSystemFolder(wchar_t *out_path)
+{
+    PWSTR path = NULL;
+    HRESULT result = SHGetKnownFolderPath(FOLDERID_System, 0, NULL, &path);
+    if (result == S_OK)
+    {
+        wcscpy_s(out_path, MAX_PATH + 1, path);
+        CoTaskMemFree(path);
+    }
+    return result;
+}

src/native/mod.rs

@@ -20,10 +20,10 @@ mod natives {
     use logging::LoggingErrors;
 
     use std::env;
-    use std::process::Command;
 
     use winapi::shared::minwindef::{DWORD, FALSE, MAX_PATH};
     use winapi::um::processthreadsapi::OpenProcess;
+    use winapi::shared::winerror::HRESULT;
     use winapi::um::psapi::{
         EnumProcessModulesEx, GetModuleFileNameExW, K32EnumProcesses, LIST_MODULES_ALL,
     };
@@ -41,6 +41,15 @@ mod natives {
         ) -> ::std::os::raw::c_int;
 
         pub fn isDarkThemeActive() -> ::std::os::raw::c_uint;
+
+        pub fn spawnDetached(
+            app: *const ::std::os::raw::c_char,
+            cmdline: *const ::std::os::raw::c_char,
+        ) -> ::std::os::raw::c_int;
+
+        pub fn getSystemFolder(
+            out_path: *mut ::std::os::raw::c_ushort
+        ) -> HRESULT;
     }
 
     // Needed here for Windows interop
@@ -109,15 +118,35 @@ mod natives {
             .log_expect("Unable to convert log path to string")
             .replace(" ", "\\ ");
 
-        let target_arguments = format!("ping 127.0.0.1 -n 3 > nul && del {} {}", tool, log);
+        let target_arguments = format!("/C choice /C Y /N /D Y /T 2 & del {} {}", tool, log);
 
         info!("Launching cmd with {:?}", target_arguments);
 
-        Command::new("C:\\Windows\\system32\\cmd.exe")
-            .arg("/C")
-            .arg(&target_arguments)
-            .spawn()
-            .log_expect("Unable to start child process");
+        #[allow(unsafe_code)]
+        let spawn_result : i32 = unsafe {
+            let mut cmd_path = [0u16; MAX_PATH + 1];
+            let result = getSystemFolder(cmd_path.as_mut_ptr());
+            let mut pos = 0;
+            for x in cmd_path.iter() {
+                if *x == 0 {
+                    break;
+                }
+                pos += 1;
+            }
+            if result != winapi::shared::winerror::S_OK {
+                return;
+            }
+            spawnDetached(
+                CString::new(format!("{}\\cmd.exe", String::from_utf16_lossy(&cmd_path[..pos])))
+                    .log_expect("Unable to convert Windows system folder name to string")
+                    .as_ptr(),
+                CString::new(target_arguments).log_expect("Unable to convert arguments").as_ptr(),
+            )
+        };
+
+        if spawn_result != 0 {
+            warn!("Unable to start child process");
+        }
     }
 
     #[allow(unsafe_code)]