Fix a lurking infinite loop in SHGetPathFromIDList.

dlls/shell32/shlfolder.c

@@ -70,14 +70,26 @@ static const WCHAR wszDotShellClassInfo[] = {
  *    TRUE if returned non-NULL value.
  *    FALSE otherwise.
  */
-BOOL SHELL32_GetCustomFolderAttribute(
-    LPCITEMIDLIST pidl, LPCWSTR pwszHeading, LPCWSTR pwszAttribute,
+static inline BOOL SHELL32_GetCustomFolderAttributeFromPath(
+    LPWSTR pwszFolderPath, LPCWSTR pwszHeading, LPCWSTR pwszAttribute,
     LPWSTR pwszValue, DWORD cchValue)
 {
     static const WCHAR wszDesktopIni[] =
             {'d','e','s','k','t','o','p','.','i','n','i',0};
     static const WCHAR wszDefault[] = {0};
+
+    PathAddBackslashW(pwszFolderPath);
+    PathAppendW(pwszFolderPath, wszDesktopIni);
+    return GetPrivateProfileStringW(pwszHeading, pwszAttribute, wszDefault, 
+                                    pwszValue, cchValue, pwszFolderPath);
+}
+
+BOOL SHELL32_GetCustomFolderAttribute(
+    LPCITEMIDLIST pidl, LPCWSTR pwszHeading, LPCWSTR pwszAttribute,
+    LPWSTR pwszValue, DWORD cchValue)
+{
     DWORD dwAttrib = FILE_ATTRIBUTE_SYSTEM;
+    WCHAR wszFolderPath[MAX_PATH];
 
     /* Hack around not having system attribute on non-Windows file systems */
     if (0)
@@ -85,20 +97,15 @@ BOOL SHELL32_GetCustomFolderAttribute(
 
     if (dwAttrib & FILE_ATTRIBUTE_SYSTEM)
     {
-        DWORD ret;
-        WCHAR wszDesktopIniPath[MAX_PATH];
-
-        if (!SHGetPathFromIDListW(pidl, wszDesktopIniPath))
+        if (!SHGetPathFromIDListW(pidl, wszFolderPath))
             return FALSE;
-        PathAppendW(wszDesktopIniPath, wszDesktopIni);
-        ret = GetPrivateProfileStringW(pwszHeading, pwszAttribute,
-            wszDefault, pwszValue, cchValue, wszDesktopIniPath);
-        return ret;
+
+        return SHELL32_GetCustomFolderAttributeFromPath(wszFolderPath, pwszHeading, 
+                                                pwszAttribute, pwszValue, cchValue);
     }
     return FALSE;
 }
 
-
 /***************************************************************************
  *  GetNextElement (internal function)
  *
@@ -277,13 +284,18 @@ HRESULT SHELL32_BindToChild (LPCITEMIDLIST pidlRoot,
         /* file system folder */
         CLSID clsidFolder = CLSID_ShellFSFolder;
         static const WCHAR wszCLSID[] = {'C','L','S','I','D',0};
-        WCHAR wszCLSIDValue[CHARS_IN_GUID];
-        LPITEMIDLIST pidlAbsolute = ILCombine (pidlRoot, pidlChild);
+        WCHAR wszCLSIDValue[CHARS_IN_GUID], wszFolderPath[MAX_PATH], *pwszPathTail = wszFolderPath;
+       
         /* see if folder CLSID should be overridden by desktop.ini file */
-        if (SHELL32_GetCustomFolderAttribute (pidlAbsolute,
+        if (pathRoot) {
+            MultiByteToWideChar(CP_ACP, 0, pathRoot, -1, wszFolderPath, MAX_PATH);
+            pwszPathTail = PathAddBackslashW(wszFolderPath);
+        }
+        MultiByteToWideChar(CP_ACP, 0, _ILGetTextPointer(pidlChild), -1, pwszPathTail, MAX_PATH);
+        if (SHELL32_GetCustomFolderAttributeFromPath (wszFolderPath,
             wszDotShellClassInfo, wszCLSID, wszCLSIDValue, CHARS_IN_GUID))
             CLSIDFromString (wszCLSIDValue, &clsidFolder);
-        ILFree (pidlAbsolute);
+
 		hr = SHELL32_CoCreateInitSF (pidlRoot, pathRoot, pidlChild,
             &clsidFolder, &IID_IShellFolder, (LPVOID *)&pSF);
     }