[ros-diffs] [hbelusca] 71880: [SHELL32] - Fix the last parameter of a StringCchCopyEx call; fix a misspelling. - Do not exclusively use GetFileAttributesEx to retrieve file attributes (for the file properties ...

Author: hbelusca
Date: Sat Jul  9 23:18:39 2016
New Revision: 71880

URL: http://svn.reactos.org/svn/reactos?rev=71880&view=rev
Log:
[SHELL32]
- Fix the last parameter of a StringCchCopyEx call; fix a misspelling.
- Do not exclusively use GetFileAttributesEx to retrieve file attributes (for the file
properties dialog). Indeed, it happens that this API (as well as GetFileAttributes), and
equivalently, NtQueryFullAttributesFile (as well as NtQueryAttributesFile), can fail on
*locked system* files (on Win2k/Win2k3/Win7, and on ROS), such as C:\pagefile.sys . See
for example
http://stackoverflow.com/questions/16772931/getfileattributes-on-locked-sys… and my
comment in CORE-10757 . Therefore to retrieve file attributes also for these files we do a
trick: we call FindFirstFile on the full path to said file. It happens that FindFirstFile
can work on locked system files, and thus we are able to retrieve their attributes (+ size
and file dates) as well!
See the code for more details.
CORE-10757 #resolve

Modified:
    trunk/reactos/dll/win32/shell32/dialogs/filedefext.cpp

Modified: trunk/reactos/dll/win32/shell32/dialogs/filedefext.cpp
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/shell32/dialogs/…
==============================================================================
--- trunk/reactos/dll/win32/shell32/dialogs/filedefext.cpp	[iso-8859-1] (original)
+++ trunk/reactos/dll/win32/shell32/dialogs/filedefext.cpp	[iso-8859-1] Sat Jul  9
23:18:39 2016
@@ -189,7 +189,7 @@
     /* Copy " bytes" to buffer */
     LPWSTR pwszEnd = pwszResult + cchWritten;
     size_t cchRemaining = cchResultMax - cchWritten;
-    StringCchCopyExW(pwszEnd, cchRemaining, L" ", &pwszEnd,
&cchRemaining, NULL);
+    StringCchCopyExW(pwszEnd, cchRemaining, L" ", &pwszEnd,
&cchRemaining, 0);
     cchWritten = LoadStringW(shell32_hInstance, IDS_BYTES_FORMAT, pwszEnd,
cchRemaining);
     cchRemaining -= cchWritten;
 
@@ -219,7 +219,7 @@
     if (lpQwSize->QuadPart < 1024)
         return pwszResult;
 
-    /* Concate " (" */
+    /* Concatenate " (" */
     UINT cchWritten = wcslen(pwszResult);
     LPWSTR pwszEnd = pwszResult + cchWritten;
     size_t cchRemaining = cchResultMax - cchWritten;
@@ -481,12 +481,50 @@
 BOOL
 CFileDefExt::InitFileAttr(HWND hwndDlg)
 {
+    BOOL Success;
+    WIN32_FIND_DATAW FileInfo; // WIN32_FILE_ATTRIBUTE_DATA
     WCHAR wszBuf[MAX_PATH];
 
     TRACE("InitFileAttr %ls\n", m_wszPath);
 
-    WIN32_FILE_ATTRIBUTE_DATA FileInfo;
-    if (GetFileAttributesExW(m_wszPath, GetFileExInfoStandard, &FileInfo))
+    /*
+     * There are situations where GetFileAttributes(Ex) can fail even if the
+     * specified path represents a file. This happens when e.g. the file is a
+     * locked system file, such as C:\pagefile.sys . In this case, the function
+     * returns INVALID_FILE_ATTRIBUTES and GetLastError returns ERROR_SHARING_VIOLATION.
+     * (this would allow us to distinguish between this failure and a failure
+     * due to the fact that the path actually refers to a directory).
+     *
+     * Because we really want to retrieve the file attributes/size/date&time,
+     * we do the following trick:
+     * - First we call GetFileAttributesEx. If it succeeds we know we have
+     *   a file or a directory, and we have retrieved its attributes.
+     * - If GetFileAttributesEx fails, we call FindFirstFile on the full path.
+     *   While we could have called FindFirstFile at first and skip GetFileAttributesEx
+     *   altogether, we do it after GetFileAttributesEx because it performs more
+     *   work to retrieve the file attributes. However it actually works even
+     *   for locked system files.
+     * - If FindFirstFile succeeds we have retrieved its attributes.
+     * - Otherwise (FindFirstFile has failed), we do not retrieve anything.
+     *
+     * The following code also relies on the fact that the first 6 members
+     * of WIN32_FIND_DATA are *exactly* the same as the WIN32_FILE_ATTRIBUTE_DATA
+     * structure. Therefore it is safe to use a single WIN32_FIND_DATA
+     * structure for both the GetFileAttributesEx and FindFirstFile calls.
+     */
+
+    Success = GetFileAttributesExW(m_wszPath,
+                                   GetFileExInfoStandard,
+                                   (LPWIN32_FILE_ATTRIBUTE_DATA)&FileInfo);
+    if (!Success)
+    {
+        HANDLE hFind = FindFirstFileW(m_wszPath, &FileInfo);
+        Success = (hFind != INVALID_HANDLE_VALUE);
+        if (Success)
+            FindClose(hFind);
+    }
+
+    if (Success)
     {
         /* Update attribute checkboxes */
         if (FileInfo.dwFileAttributes & FILE_ATTRIBUTE_READONLY)