// Copy a menu onto the beginning or end of another menu
// Adds uIDAdjust to each menu ID (pass in 0 for no adjustment)
// Will not add any item whose adjusted ID is greater than uMaxIDAdjust
// (pass in 0xffff to allow everything)
// Returns one more than the maximum adjusted ID that is used
//

UINT WINAPI Shell_MergeMenus(HMENU hmDst, HMENU hmSrc, UINT uInsert, UINT uIDAdjust, UINT uIDAdjustMax, ULONG uFlags)
{
    int nItem;
    HMENU hmSubMenu;
    BOOL bAlreadySeparated;
    MENUITEMINFO miiSrc;
    TCHAR szName[256];
    UINT uTemp, uIDMax = uIDAdjust;

    if (!hmDst || !hmSrc)
    {
        goto MM_Exit;
    }

    nItem = GetMenuItemCount(hmDst);
    if (uInsert >= (UINT)nItem)
    {
        uInsert = (UINT)nItem;
        bAlreadySeparated = TRUE;
    }
    else
    {
        bAlreadySeparated = _SHIsMenuSeparator(hmDst, uInsert);;
    }

    if ((uFlags & MM_ADDSEPARATOR) && !bAlreadySeparated)
    {
        // Add a separator between the menus
        InsertMenu(hmDst, uInsert, MF_BYPOSITION | MF_SEPARATOR, 0, NULL);
        bAlreadySeparated = TRUE;
    }

    // Go through the menu items and clone them
    for (nItem = GetMenuItemCount(hmSrc) - 1; nItem >= 0; nItem--)
    {
        miiSrc.cbSize = SIZEOF(MENUITEMINFO);
        miiSrc.fMask = MIIM_STATE | MIIM_ID | MIIM_SUBMENU | MIIM_CHECKMARKS | MIIM_TYPE | MIIM_DATA;
        // We need to reset this every time through the loop in case
        // menus DON'T have IDs
        miiSrc.fType = MFT_STRING;
        miiSrc.dwTypeData = szName;
        miiSrc.dwItemData = 0;
        miiSrc.cch        = ARRAYSIZE(szName);

        if (!GetMenuItemInfo(hmSrc, nItem, TRUE, &miiSrc))
        {
            continue;
        }

        // If it's a separator, then add it.  If the separator has a
        // submenu, then the caller is smoking crash and needs their butt kicked.
        if ((miiSrc.fType & MFT_SEPARATOR) && EVAL(!miiSrc.hSubMenu))
        {
            // This is a separator; don't put two of them in a row
            if (bAlreadySeparated && miiSrc.wID == -1 && !(uFlags & MM_DONTREMOVESEPS))
            {
                continue;
            }

            bAlreadySeparated = TRUE;
        }
        else if (miiSrc.hSubMenu)
        {
            if (uFlags & MM_SUBMENUSHAVEIDS)
            {
                // Adjust the ID and check it
                miiSrc.wID += uIDAdjust;
                if (miiSrc.wID > uIDAdjustMax)
                {
                    continue;
                }

                if (uIDMax <= miiSrc.wID)
                {
                    uIDMax = miiSrc.wID + 1;
                }
            }
            else
            {
                // Don't set IDs for submenus that didn't have
                // them already
                miiSrc.fMask &= ~MIIM_ID;
            }

            hmSubMenu = miiSrc.hSubMenu;
            miiSrc.hSubMenu = CreatePopupMenu();
            if (!miiSrc.hSubMenu)
            {
                goto MM_Exit;
            }

            uTemp = Shell_MergeMenus(miiSrc.hSubMenu, hmSubMenu, 0, uIDAdjust,
                uIDAdjustMax, uFlags&MM_SUBMENUSHAVEIDS);
            if (uIDMax <= uTemp)
            {
                uIDMax = uTemp;
            }

            bAlreadySeparated = FALSE;
        }
        else
        {
            // Adjust the ID and check it
            miiSrc.wID += uIDAdjust;
            if (miiSrc.wID > uIDAdjustMax)
            {
                continue;
            }

            if (uIDMax <= miiSrc.wID)
            {
                uIDMax = miiSrc.wID + 1;
            }

            bAlreadySeparated = FALSE;
        }

        if (!EVAL(InsertMenuItem(hmDst, uInsert, TRUE, &miiSrc)))
        {
            goto MM_Exit;
        }
    }

    // Ensure the correct number of separators at the beginning of the
    // inserted menu items
    if (uInsert == 0)
    {
        if (bAlreadySeparated && !(uFlags & MM_DONTREMOVESEPS))
        {
            DeleteMenu(hmDst, uInsert, MF_BYPOSITION);
        }
    }
    else
    {
        if (_SHIsMenuSeparator(hmDst, uInsert-1))
        {
            if (bAlreadySeparated && !(uFlags & MM_DONTREMOVESEPS))
            {
                DeleteMenu(hmDst, uInsert, MF_BYPOSITION);
            }
        }
        else
        {
            if ((uFlags & MM_ADDSEPARATOR) && !bAlreadySeparated)
            {
                // Add a separator between the menus
                InsertMenu(hmDst, uInsert, MF_BYPOSITION | MF_SEPARATOR, 0, NULL);
            }
        }
    }

MM_Exit:
#ifdef DEBUG
    DBCheckMenu(hmDst);
#endif
    return(uIDMax);
}