Correct GetNumberFormat for negative numbers with e.g. 3 leading

dlls/kernel/lcformat.c

@@ -1134,7 +1134,7 @@ GetNumberFormatW_Error:
 
     dwState |= NF_DIGITS_OUT;
     dwCurrentGroupCount++;
-    if (szSrc >= lpszValue && dwCurrentGroupCount == dwGroupCount)
+    if (szSrc >= lpszValue && dwCurrentGroupCount == dwGroupCount && *szSrc != '-')
     {
       LPWSTR lpszGrp = lpFormat->lpThousandSep + strlenW(lpFormat->lpThousandSep) - 1;
 

dlls/kernel/tests/locale.c

@@ -660,6 +660,10 @@ static void test_GetNumberFormatA()
   ret = GetNumberFormatA(lcid, NUO, input, NULL, buffer, COUNTOF(buffer));
   EXPECT_VALID; EXPECT_LENA; EXPECT_EQA;
 
+  STRINGSA("-353","-353.00"); /* test for off by one error in grouping */
+  ret = GetNumberFormatA(lcid, NUO, input, NULL, buffer, COUNTOF(buffer));
+  EXPECT_VALID; EXPECT_LENA; EXPECT_EQA;
+
   STRINGSA("2353.1","2,353.10"); /* Valid real number */
   ret = GetNumberFormatA(lcid, NUO, input, NULL, buffer, COUNTOF(buffer));
   EXPECT_VALID; EXPECT_LENA; EXPECT_EQA;