[SHELL32] Correctly implement common desktop items PIDL (reactos#7730)

The current implementation is broken, if a file/folder exists in both places, you always get the user item.

CORE-19861

Author: whindsaks

dll/win32/shell32/folders/CDesktopFolder.cpp

@@ -49,11 +49,17 @@ static BOOL IsSelf(UINT cidl, PCUITEMID_CHILD_ARRAY apidl)
 
 static const CLSID* IsRegItem(PCUITEMID_CHILD pidl)
 {
-    if (pidl && pidl->mkid.cb == 2 + 2 + sizeof(CLSID) && pidl->mkid.abID[0] == PT_GUID)
+    if (pidl && pidl->mkid.cb == 2 + 2 + sizeof(CLSID) && pidl->mkid.abID[0] == PT_DESKTOP_REGITEM)
         return (const CLSID*)(&pidl->mkid.abID[2]);
     return NULL;
 }
 
+static inline void MarkAsCommonItem(LPITEMIDLIST pidl)
+{
+    ASSERT(_ILGetFSType(pidl) & PT_FS);
+    ((PIDLDATA*)pidl->mkid.abID)->type |= PT_FS_COMMON_FLAG;
+}
+
 STDMETHODIMP
 CDesktopFolder::ShellUrlParseDisplayName(
     HWND hwndOwner,
@@ -201,8 +207,19 @@ class CDesktopFolderEnum :
 
             /* Enumerate the items in the two fs folders */
             AppendItemsFromEnumerator(pDesktopEnumerator);
+            ENUMLIST *pCommon = this->mpLast;
             AppendItemsFromEnumerator(pCommonDesktopEnumerator);
-
+            if (pCommon != this->mpLast) // Any common items added?
+            {
+                ENUMLIST fake;
+                if (!pCommon) // In the unlikely case that there are no RegItems nor user items
+                {
+                    fake.pNext = this->mpFirst;
+                    pCommon = &fake;
+                }
+                while ((pCommon = pCommon->pNext) != NULL)
+                    MarkAsCommonItem(pCommon->pidl);
+            }
             return S_OK;
         }
 
@@ -281,22 +298,20 @@ HRESULT WINAPI CDesktopFolder::FinalConstruct()
 
 HRESULT CDesktopFolder::_GetSFFromPidl(LPCITEMIDLIST pidl, IShellFolder2** psf)
 {
-    WCHAR szFileName[MAX_PATH];
-
-    if (_ILIsSpecialFolder(pidl))
+    if (IsRegItem(pidl))
         return m_regFolder->QueryInterface(IID_PPV_ARG(IShellFolder2, psf));
-
-    lstrcpynW(szFileName, sPathTarget, MAX_PATH - 1);
-    PathAddBackslashW(szFileName);
-    int cLen = wcslen(szFileName);
-
-    if (!_ILSimpleGetTextW(pidl, szFileName + cLen, MAX_PATH - cLen))
-        return E_FAIL;
-
-    if (GetFileAttributes(szFileName) == INVALID_FILE_ATTRIBUTES)
-        return m_SharedDesktopFSFolder->QueryInterface(IID_PPV_ARG(IShellFolder2, psf));
+#if DBG
+    if (_ILIsDesktop(pidl))
+    {
+        FIXME("Desktop is unexpected here!\n");
+    }
     else
-        return m_DesktopFSFolder->QueryInterface(IID_PPV_ARG(IShellFolder2, psf));
+    {
+        ASSERT(!_ILIsSpecialFolder(pidl));
+    }
+#endif
+    IShellFolder *pSF = IsCommonItem(pidl) ? m_SharedDesktopFSFolder : m_DesktopFSFolder;
+    return pSF->QueryInterface(IID_PPV_ARG(IShellFolder2, psf));
 }
 
 HRESULT CDesktopFolder::_ParseDisplayNameByParent(
@@ -502,6 +517,8 @@ HRESULT WINAPI CDesktopFolder::ParseDisplayName(
                                                        pchEaten,
                                                        ppidl,
                                                        pdwAttributes);
+        if (SUCCEEDED(hr))
+            MarkAsCommonItem(*ppidl);
     }
 
     if (FAILED(hr) && bCreate && m_DesktopFSFolder)
@@ -604,7 +621,10 @@ HRESULT WINAPI CDesktopFolder::CompareIDs(LPARAM lParam, PCUIDLIST_RELATIVE pidl
     if (_ILIsSpecialFolder(pidl1) || _ILIsSpecialFolder(pidl2))
         return m_regFolder->CompareIDs(lParam, pidl1, pidl2);
 
-    return m_DesktopFSFolder->CompareIDs(lParam, pidl1, pidl2);
+    HRESULT ret = m_DesktopFSFolder->CompareIDs(lParam, pidl1, pidl2);
+    if (ret == 0 && ((lParam & SHCIDS_COLUMNMASK) == SHFSF_COL_NAME || (lParam & (SHCIDS_ALLFIELDS | SHCIDS_CANONICALONLY))))
+        ret = MAKE_COMPARE_HRESULT(IsCommonItem(pidl1) - IsCommonItem(pidl2));
+    return ret;
 }
 
 /**************************************************************************

dll/win32/shell32/folders/CDesktopFolder.h

@@ -75,6 +75,8 @@ class CDesktopFolder :
         ~CDesktopFolder();
         HRESULT WINAPI FinalConstruct();
 
+        static inline BOOL IsCommonItem(LPCITEMIDLIST pidl) { return _ILGetFSType(pidl) & PT_FS_COMMON_FLAG; }
+
         // *** IShellFolder methods ***
         STDMETHOD(ParseDisplayName)(HWND hwndOwner, LPBC pbc, LPOLESTR lpszDisplayName, DWORD *pchEaten, PIDLIST_RELATIVE *ppidl, DWORD *pdwAttributes) override;
         STDMETHOD(EnumObjects)(HWND hwndOwner, DWORD dwFlags, LPENUMIDLIST *ppEnumIDList) override;

dll/win32/shell32/wine/pidl.c

@@ -2293,9 +2293,6 @@ static LPWSTR _ILGetTextPointerW(LPCITEMIDLIST pidl)
         /*return (LPSTR)&(pdata->u.drive.szDriveName);*/
         return NULL;
 
-    case PT_FOLDER:
-    case PT_FOLDER1:
-    case PT_VALUE:
     case PT_IESPECIAL1:
     case PT_IESPECIAL2:
         /*return (LPSTR)&(pdata->u.file.szNames);*/
@@ -2327,27 +2324,25 @@ LPSTR _ILGetTextPointer(LPCITEMIDLIST pidl)
 {
     /* TRACE(pidl,"(pidl%p)\n", pidl);*/
 
+    PIDLTYPE type;
     LPPIDLDATA pdata = _ILGetDataPointer(pidl);
-
     if (!pdata)
         return NULL;
 
+    type = _ILGetFSType(pidl);
+    if (type && !(type & PT_FS_UNICODE_FLAG))
+        return pdata->u.file.szNames;
+
+    if (_ILIsDrive(pidl))
+        return pdata->u.drive.szDriveName;
+
     switch (pdata->type)
     {
     case PT_GUID:
     case PT_SHELLEXT:
     case PT_YAGUID:
         return NULL;
 
-    case PT_DRIVE:
-    case PT_DRIVE1:
-    case PT_DRIVE2:
-    case PT_DRIVE3:
-        return pdata->u.drive.szDriveName;
-
-    case PT_FOLDER:
-    case PT_FOLDER1:
-    case PT_VALUE:
     case PT_IESPECIAL1:
     case PT_IESPECIAL2:
         return pdata->u.file.szNames;
@@ -2370,15 +2365,18 @@ static LPSTR _ILGetSTextPointer(LPCITEMIDLIST pidl)
 {
     /* TRACE(pidl,"(pidl%p)\n", pidl); */
 
+    PIDLTYPE type;
     LPPIDLDATA pdata =_ILGetDataPointer(pidl);
-
     if (!pdata)
         return NULL;
 
-    switch (pdata->type)
+    type = pdata->type;
+    if (_ILGetFSType(pidl) && !(type & PT_FS_UNICODE_FLAG))
+        type = PT_FS;
+
+    switch (type)
     {
-    case PT_FOLDER:
-    case PT_VALUE:
+    case PT_FS:
     case PT_IESPECIAL1:
     case PT_IESPECIAL2:
         return pdata->u.file.szNames + strlen (pdata->u.file.szNames) + 1;
@@ -2567,24 +2565,13 @@ BOOL _ILGetExtension(LPCITEMIDLIST pidl, LPWSTR pOut, UINT uOutSize)
  */
 DWORD _ILGetFileAttributes(LPCITEMIDLIST pidl, LPWSTR pOut, UINT uOutSize)
 {
-    LPPIDLDATA pData = _ILGetDataPointer(pidl);
-    WORD wAttrib = 0;
-    int i;
-
-    if (!pData)
-        return 0;
-
-    switch(pData->type)
-    {
-    case PT_FOLDER:
-    case PT_VALUE:
-        wAttrib = pData->u.file.uFileAttribs;
-        break;
-    }
+    DWORD wAttrib = 0;
+    if (_ILGetFSType(pidl))
+        wAttrib = _ILGetDataPointer(pidl)->u.file.uFileAttribs;
 
-    if(uOutSize >= 6)
+    if (uOutSize >= 6)
     {
-        i=0;
+        UINT i = 0;
         if(wAttrib & FILE_ATTRIBUTE_READONLY)
             pOut[i++] = L'R';
         if(wAttrib & FILE_ATTRIBUTE_HIDDEN)

dll/win32/shell32/wine/pidl.h

@@ -112,6 +112,7 @@ extern "C" {
 #define PT_FS_FOLDER_FLAG       0x01
 #define PT_FS_FILE_FLAG         0x02
 #define PT_FS_UNICODE_FLAG      0x04
+#define PT_FS_COMMON_FLAG       0x08
 //      PT_NET_REGITEM          0x4? // => SHDID_NET_OTHER
 #define PT_CONTROLS_OLDREGITEM  0x70
 #define PT_CONTROLS_NEWREGITEM  0x71