[PATCH v7 3/8] kernelbase: Factor opening a subkey out of open_key().

[Sven Baars]

From: Sven Baars

---
 dlls/kernelbase/registry.c | 117 ++++++++++++++++++++++---------------
 1 file changed, 71 insertions(+), 46 deletions(-)

diff --git a/dlls/kernelbase/registry.c b/dlls/kernelbase/registry.c
index 668bceac57a..2e3726096ad 100644
--- a/dlls/kernelbase/registry.c
+++ b/dlls/kernelbase/registry.c
@@ -214,14 +214,71 @@ static NTSTATUS create_key( HKEY *retkey, ACCESS_MASK access, OBJECT_ATTRIBUTES
     return status;
 }

+static NTSTATUS open_subkey( HKEY *subkey, HKEY root, UNICODE_STRING *name, DWORD options, ACCESS_MASK access )
+{
+    DWORD i = 0, len = name->Length / sizeof(WCHAR);
+    WCHAR *buffer = name->Buffer;
+    OBJECT_ATTRIBUTES attr;
+    UNICODE_STRING str;
+    NTSTATUS status = 0;
+
+    attr.Length = sizeof(attr);
+    attr.RootDirectory = (HANDLE)root;
+    attr.ObjectName = &str;
+    attr.Attributes = 0;
+    attr.SecurityDescriptor = NULL;
+    attr.SecurityQualityOfService = NULL;
+
+    if (buffer[0] == '\') return STATUS_OBJECT_PATH_INVALID;
+    while (i < len && buffer[i] != '\') i++;
+
+    str.Buffer = name->Buffer;
+    str.Length = i * sizeof(WCHAR);
+
+    if (i == len)
+    {
+        if (options & REG_OPTION_OPEN_LINK) attr.Attributes |= OBJ_OPENLINK;
+    }
+    else
+    {
+        if (!(options & REG_OPTION_OPEN_LINK)) attr.Attributes &= ~OBJ_OPENLINK;
+        options &= ~REG_OPTION_OPEN_LINK;
+    }
+
+    status = NtOpenKeyEx( (HANDLE *)subkey, access, &attr, options );
+    if (status == STATUS_PREDEFINED_HANDLE)
+    {
+        *subkey = get_perflib_key( *subkey );
+        status = STATUS_SUCCESS;
+    }
+
+    if (!status)
+    {
+        while (i < len && buffer[i] == '\') i++;
+
+        name->Buffer += i;
+        name->Length -= i * sizeof(WCHAR);
+
+        if (!is_wow6432node( name ))
+        {
+            HKEY wow6432node = open_wow6432node( *subkey );
+            if (wow6432node)
+            {
+                NtClose( *subkey );
+                *subkey = wow6432node;
+            }
+        }
+    }
+
+    return status;
+}
+
 /* wrapper for NtOpenKeyEx to handle Wow6432 nodes */
 static NTSTATUS open_key( HKEY *retkey, DWORD options, ACCESS_MASK access, OBJECT_ATTRIBUTES *attr )
 {
-    NTSTATUS status;
-    HANDLE subkey, root = attr->RootDirectory;
-    WCHAR *buffer = attr->ObjectName->Buffer;
-    DWORD i, len = attr->ObjectName->Length / sizeof(WCHAR);
-    UNICODE_STRING str;
+    HKEY root = attr->RootDirectory, subkey, subkey_root = root;
+    UNICODE_STRING name;
+    NTSTATUS status = 0;

*retkey = NULL;

@@ -237,51 +294,19 @@ static NTSTATUS open_key( HKEY *retkey, DWORD options, ACCESS_MASK access, OBJEC
         return status;
     }

-    attr->ObjectName = &str;
+    name.Buffer = attr->ObjectName->Buffer;
+    name.Length = attr->ObjectName->Length;

-    while (len)
+    while (!status && name.Length)
     {
-        i = 0;
-        if (buffer[0] == '\') return STATUS_OBJECT_PATH_INVALID;
-        while (i < len && buffer[i] != '\') i++;
-
-        str.Buffer = buffer;
-        str.Length = i * sizeof(WCHAR);
+        status = open_subkey( &subkey, subkey_root, &name, options, access );
+        if (subkey_root && subkey_root != root) NtClose( subkey_root );
+        subkey_root = subkey;
+    }

-        if (i == len)
-        {
-            if (options & REG_OPTION_OPEN_LINK) attr->Attributes |= OBJ_OPENLINK;
-            status = NtOpenKeyEx( &subkey, access, attr, options );
-        }
-        else
-        {
-            if (!(options & REG_OPTION_OPEN_LINK)) attr->Attributes &= ~OBJ_OPENLINK;
-            status = NtOpenKeyEx( &subkey, access, attr, options & ~REG_OPTION_OPEN_LINK );
-        }
-        if (attr->RootDirectory != root) NtClose( attr->RootDirectory );
-        if (status) return status;
-        attr->RootDirectory = subkey;
-        while (i < len && buffer[i] == '\') i++;
-        buffer += i;
-        len -= i;
+    if (!status)
+        *retkey = subkey_root;

-        str.Buffer = buffer;
-        str.Length = len * sizeof(WCHAR);
-        if (!is_wow6432node( &str ))
-        {
-            if ((subkey = open_wow6432node( attr->RootDirectory )))
-            {
-                NtClose( attr->RootDirectory );
-                attr->RootDirectory = subkey;
-            }
-        }
-    }
-    if (status == STATUS_PREDEFINED_HANDLE)
-    {
-        attr->RootDirectory = get_perflib_key( attr->RootDirectory );
-        status = STATUS_SUCCESS;
-    }
-    *retkey = attr->RootDirectory;
     return status;
 }