[PATCH v2] shell32: handle writing an iconresource entry in SHGetSetFolderCustomSettings

[Louis Lenders]

v2: -fixed a misleading comment
    - only print fixme when needed

This fixes bug https://bugs.winehq.org/show_bug.cgi?id=44959

I also tried to write a test, that test passes on the 32-bit testbots, but somehow the last test fails on 64-bit testbots and i don`t know why.
Test is at https://testbot.winehq.org/GetFile.pl?JobKey=37794&StepKey=1

Also win2003 testbot gives strange errors in a test above this one that i don`t get. 
See for example https://testbot.winehq.org/JobDetails.pl?Key=37794. 
So this goes without submitted test for now

Signed-off-by: Louis Lenders 
---
 dlls/shell32/shlfolder.c | 32 +++++++++++++++++++++++++++++---
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/dlls/shell32/shlfolder.c b/dlls/shell32/shlfolder.c
index 9143f1e..c94c90e 100644
--- a/dlls/shell32/shlfolder.c
+++ b/dlls/shell32/shlfolder.c
@@ -607,12 +607,38 @@ HRESULT WINAPI SHOpenFolderAndSelectItems( PCIDLIST_ABSOLUTE pidlFolder, UINT ci
 /***********************************************************************
  *  SHGetSetFolderCustomSettings
  *
- *   Only Unicode above Server 2003
+ *   Only Unicode above Server 2003, writes/reads from a desktop.ini
  */
 HRESULT WINAPI SHGetSetFolderCustomSettings( LPSHFOLDERCUSTOMSETTINGS fcs, PCWSTR path, DWORD flag )
 {
-    FIXME("%p %s 0x%x: stub\n", fcs, debugstr_w(path), flag);
-    return E_NOTIMPL;
+    static const WCHAR iconresourceW[] = {'I','c','o','n','R','e','s','o','u','r','c','e',0};
+    static const WCHAR desktop_iniW[] = {'D','e','s','k','t','o','p','.','i','n','i',0};
+    WCHAR bufferW[MAX_PATH]= {0};
+    HRESULT hr;
+
+    hr = E_FAIL;
+
+    if (flag & FCS_FORCEWRITE)
+    {
+        if (fcs->dwMask & FCSM_ICONFILE)
+        {
+            lstrcpyW(bufferW, path);
+            PathAddBackslashW(bufferW);
+            lstrcatW(bufferW, desktop_iniW);
+
+            if (WritePrivateProfileStringW(wszDotShellClassInfo, iconresourceW, fcs->pszIconFile, bufferW))
+            {
+                TRACE("Wrote an iconresource entry %s into %s\n", debugstr_w(fcs->pszIconFile), debugstr_w(bufferW));
+                hr = S_OK;
+            }
+            else
+                ERR("Failed to write (to) Desktop.ini file\n");
+        }
+    }
+    else
+        FIXME("%p %s 0x%x: stub\n", fcs, debugstr_w(path), flag);
+
+    return hr;
 }

/***********************************************************************