odbccp32: Handle NULL parameter in SQLWritePrivateProfileStringW.

dlls/odbccp32/odbccp32.c

@@ -1561,6 +1561,7 @@ BOOL WINAPI SQLWriteFileDSN(LPCSTR lpszFileName, LPCSTR lpszAppName,
 BOOL WINAPI SQLWritePrivateProfileStringW(LPCWSTR lpszSection, LPCWSTR lpszEntry,
                LPCWSTR lpszString, LPCWSTR lpszFilename)
 {
+    static const WCHAR empty[] = {0};
     LONG ret;
     HKEY hkey;
 
@@ -1584,7 +1585,10 @@ BOOL WINAPI SQLWritePrivateProfileStringW(LPCWSTR lpszSection, LPCWSTR lpszEntry
 
               if ((ret = RegCreateKeyW(hkeyfilename, lpszSection, &hkey_section)) == ERROR_SUCCESS)
               {
-                  ret = RegSetValueExW(hkey_section, lpszEntry, 0, REG_SZ, (BYTE*)lpszString, (lstrlenW(lpszString)+1)*sizeof(WCHAR));
+                  if(lpszString)
+                      ret = RegSetValueExW(hkey_section, lpszEntry, 0, REG_SZ, (BYTE*)lpszString, (lstrlenW(lpszString)+1)*sizeof(WCHAR));
+                  else
+                      ret = RegSetValueExW(hkey_section, lpszEntry, 0, REG_SZ, (BYTE*)empty, sizeof(empty));
                   RegCloseKey(hkey_section);
               }
 

dlls/odbccp32/tests/misc.c

@@ -171,6 +171,9 @@ static void test_SQLWritePrivateProfileString(void)
    {
         HKEY hkey;
 
+        ret = SQLWritePrivateProfileString("wineodbc", "testing" , NULL, "odbc.ini");
+        ok(ret, "SQLWritePrivateProfileString failed\n");
+
         reg_ret = RegOpenKeyExW(HKEY_CURRENT_USER, odbc_key, 0, KEY_READ, &hkey);
         ok(reg_ret == ERROR_SUCCESS, "RegOpenKeyExW failed\n");
         if(reg_ret == ERROR_SUCCESS)