From 0d12f2c89227b25665b995a667b03e1b63051014 Mon Sep 17 00:00:00 2001
From: Mikhail Filippov <mikhail@filippov.me>
Date: Thu, 19 Aug 2021 22:36:31 +0300
Subject: [PATCH] Add RegLoadAppKeyW support

---
 CHANGES.md                                    |  2 +-
 .../com/sun/jna/platform/win32/Advapi32.java  | 23 +++++++++++++++++++
 .../sun/jna/platform/win32/Advapi32Util.java  | 22 ++++++++++++++++++
 .../jna/platform/win32/Advapi32UtilTest.java  | 12 ++++++++++
 4 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/CHANGES.md b/CHANGES.md
index d662b74b9c..dca66650de 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -7,7 +7,7 @@ Next Release (5.10.0)
 
 Features
 --------
-
+* [#1377](https://github.com/java-native-access/jna/pull/1377): Add `RegLoadAppKey` to `c.s.j.p.win32.Advapi32` and `registryLoadAppKey` to `c.s.j.p.win32.Advapi32Util` - [@mfilippov](https://github.com/mfilippov).
 
 Bug Fixes
 ---------
diff --git a/contrib/platform/src/com/sun/jna/platform/win32/Advapi32.java b/contrib/platform/src/com/sun/jna/platform/win32/Advapi32.java
index e9c1b23f43..07e5992b7a 100755
--- a/contrib/platform/src/com/sun/jna/platform/win32/Advapi32.java
+++ b/contrib/platform/src/com/sun/jna/platform/win32/Advapi32.java
@@ -82,6 +82,7 @@ public interface Advapi32 extends StdCallLibrary {
     int RRF_RT_REG_NONE = 0x00000001;
     int RRF_RT_REG_QWORD = 0x00000040;
     int RRF_RT_REG_SZ = 0x00000002;
+    int REG_PROCESS_APPKEY = 0x00000001;
 
     /**
      * LOGON_WITH_PROFILE: 0x00000001<br>
@@ -854,6 +855,28 @@ boolean GetTokenInformation(HANDLE tokenHandle,
     int RegOpenKeyEx(HKEY hKey, String lpSubKey, int ulOptions,
                      int samDesired, HKEYByReference phkResult);
 
+    /**
+     * The RegLoadAppKey function loads the specified registry hive
+     * as an application hive.
+     *
+     * @param lpFile
+     *            The name of the hive file.
+     *            If the file does not exist, an empty hive file is created
+     *            with the specified name.
+     * @param phkResult
+     *            Pointer to the handle for the root key of the loaded hive.
+     * @param samDesired
+     *            Access mask that specifies the desired access rights to the
+     * @param dwOptions
+     *            If this parameter is REG_PROCESS_APPKEY,
+     *            the hive cannot be loaded again while it is loaded by the caller.
+     *            This prevents access to this registry hive by another caller.
+     * @param Reserved
+     *            Reserved; must be zero.
+     */
+    int RegLoadAppKey(String lpFile, HKEYByReference phkResult,
+                       int samDesired, int dwOptions, int Reserved);
+
     /**
      * Establishes a connection to a predefined registry key on another
      * computer.
diff --git a/contrib/platform/src/com/sun/jna/platform/win32/Advapi32Util.java b/contrib/platform/src/com/sun/jna/platform/win32/Advapi32Util.java
index 73e773bcbc..304fe21a3c 100755
--- a/contrib/platform/src/com/sun/jna/platform/win32/Advapi32Util.java
+++ b/contrib/platform/src/com/sun/jna/platform/win32/Advapi32Util.java
@@ -2076,6 +2076,28 @@ public static HKEYByReference registryGetKey(HKEY root, String keyPath,
         return phkKey;
     }
 
+    /**
+     * Loads the specified registry hive as an application hive.
+     *
+     * @param fileName
+     *            Path to the file
+     * @param samDesired
+     *            Access mask that specifies the desired access rights to the
+     * @param dwOptions
+     *            If this parameter is REG_PROCESS_APPKEY,
+     *            the hive cannot be loaded again while it is loaded by the caller.
+     *            This prevents access to this registry hive by another caller.
+     */
+    public static HKEYByReference registryLoadAppKey(String fileName, int samDesired, int dwOptions) {
+        HKEYByReference phkKey = new HKEYByReference();
+        int rc = Advapi32.INSTANCE.RegLoadAppKey(fileName, phkKey, samDesired, dwOptions, 0);
+        if (rc != W32Errors.ERROR_SUCCESS) {
+            throw new Win32Exception(rc);
+        }
+
+        return phkKey;
+    }
+
     /**
      * Close the registry key
      *
diff --git a/contrib/platform/test/com/sun/jna/platform/win32/Advapi32UtilTest.java b/contrib/platform/test/com/sun/jna/platform/win32/Advapi32UtilTest.java
index 542e314c29..2297d2c380 100755
--- a/contrib/platform/test/com/sun/jna/platform/win32/Advapi32UtilTest.java
+++ b/contrib/platform/test/com/sun/jna/platform/win32/Advapi32UtilTest.java
@@ -29,6 +29,7 @@
 
 import java.io.File;
 import java.io.FileWriter;
+import java.nio.file.Files;
 import java.util.Map;
 import java.util.TreeMap;
 
@@ -605,6 +606,17 @@ public void testRegistryGetCloseKey() {
         Advapi32Util.registryDeleteKey(WinReg.HKEY_CURRENT_USER, "Software", "JNA");
     }
 
+    public void testRegistryLoadAppKey() throws Exception {
+        File tempDir = Files.createTempDirectory("testRegistryLoadAppKey").toFile();
+        File registryFile = new File(tempDir, "privateregistry.bin");
+        HKEYByReference phkKey = Advapi32Util.registryLoadAppKey(registryFile.getAbsolutePath(), WinNT.KEY_ALL_ACCESS, 0);
+        Advapi32Util.registryCreateKey(phkKey.getValue(), "Test");
+        Advapi32Util.registryDeleteKey(phkKey.getValue(), "Test");
+        Advapi32Util.registryCloseKey(phkKey.getValue());
+        registryFile.delete();
+        tempDir.delete();
+    }
+
     public void testRegistryGetValues() {
         String uu = "A\\u00ea\\u00f1\\u00fcC";
         Advapi32Util.registryCreateKey(WinReg.HKEY_CURRENT_USER, "Software", "JNA");