[PATCH v14 1/6] kernelbase: Restructure the open_key() loop.

[Sven Baars]

From: Sven Baars

---
 dlls/kernelbase/registry.c | 51 +++++++++++++++++++-------------------
 1 file changed, 26 insertions(+), 25 deletions(-)

diff --git a/dlls/kernelbase/registry.c b/dlls/kernelbase/registry.c
index 0137cbe6cad..0f629ab2d36 100644
--- a/dlls/kernelbase/registry.c
+++ b/dlls/kernelbase/registry.c
@@ -100,7 +100,8 @@ static inline BOOL is_version_nt(void)

static BOOL is_wow6432node( const UNICODE_STRING *name )
 {
-    return (name->Length == 11 * sizeof(WCHAR) && !wcsnicmp( name->Buffer, L"Wow6432Node", 11 ));
+    DWORD len = name->Length / sizeof(WCHAR);
+    return (len >= 11 && !wcsnicmp( name->Buffer, L"Wow6432Node\", min( len, 12 ) ));
 }

/* open the Wow6432Node subkey of the specified key */
@@ -220,7 +221,7 @@ static NTSTATUS open_key( HKEY *retkey, DWORD options, ACCESS_MASK access, OBJEC
     BOOL force_wow32 = is_win64 && (access & KEY_WOW64_32KEY);
     HANDLE subkey, root = attr->RootDirectory;
     WCHAR *buffer = attr->ObjectName->Buffer;
-    DWORD pos = 0, i = 0, len = attr->ObjectName->Length / sizeof(WCHAR);
+    DWORD i, len = attr->ObjectName->Length / sizeof(WCHAR);
     UNICODE_STRING str;

*retkey = NULL;
@@ -237,24 +238,17 @@ static NTSTATUS open_key( HKEY *retkey, DWORD options, ACCESS_MASK access, OBJEC
         return status;
     }

-    if (len && buffer[0] == '\') return STATUS_OBJECT_PATH_INVALID;
-    while (i < len && buffer[i] != '\') i++;
     attr->ObjectName = &str;

-    for (;;)
+    while (len)
     {
-        str.Buffer = buffer + pos;
-        str.Length = (i - pos) * sizeof(WCHAR);
-        if (force_wow32 && pos)
-        {
-            if (is_wow6432node( &str )) force_wow32 = FALSE;
-            else if ((subkey = open_wow6432node( attr->RootDirectory )))
-            {
-                if (attr->RootDirectory != root) NtClose( attr->RootDirectory );
-                attr->RootDirectory = subkey;
-                force_wow32 = FALSE;
-            }
-        }
+        i = 0;
+        if (buffer[0] == '\') return STATUS_OBJECT_PATH_INVALID;
+        while (i < len && buffer[i] != '\') i++;
+
+        str.Buffer = buffer;
+        str.Length = i * sizeof(WCHAR);
+
         if (i == len)
         {
             if (options & REG_OPTION_OPEN_LINK) attr->Attributes |= OBJ_OPENLINK;
@@ -268,15 +262,22 @@ static NTSTATUS open_key( HKEY *retkey, DWORD options, ACCESS_MASK access, OBJEC
         if (attr->RootDirectory != root) NtClose( attr->RootDirectory );
         if (status) return status;
         attr->RootDirectory = subkey;
-        if (i == len) break;
         while (i < len && buffer[i] == '\') i++;
-        pos = i;
-        while (i < len && buffer[i] != '\') i++;
-    }
-    if (force_wow32 && (subkey = open_wow6432node( attr->RootDirectory )))
-    {
-        if (attr->RootDirectory != root) NtClose( attr->RootDirectory );
-        attr->RootDirectory = subkey;
+        buffer += i;
+        len -= i;
+
+        if (force_wow32)
+        {
+            str.Buffer = buffer;
+            str.Length = len * sizeof(WCHAR);
+            if (is_wow6432node( &str )) force_wow32 = FALSE;
+            else if ((subkey = open_wow6432node( attr->RootDirectory )))
+            {
+                NtClose( attr->RootDirectory );
+                attr->RootDirectory = subkey;
+                force_wow32 = FALSE;
+            }
+        }
     }
     if (status == STATUS_PREDEFINED_HANDLE)
     {