windows.cfg: Fixed FP for invalidFunctionArg in second argument of _getcwd(). Reference: https://docs.microsoft.com/en-us/previous-versions/sf98bd4y(v%3Dvs.140)

cfg/windows.cfg

@@ -1846,7 +1846,8 @@
     </arg>
     <arg nr="2" direction="in">
       <not-uninit/>
-      <valid>1:</valid>
+      <!-- Zero length is allowed in case the first argument is NULL. -->
+      <valid>0:</valid>
       <not-bool/>
     </arg>
   </function>

test/cfg/windows.cpp

@@ -8,6 +8,19 @@
 //
 
 #include <windows.h>
+#include <direct.h>
+#include <stdlib.h>
+
+void invalidFunctionArg__getcwd(char * buffer)
+{
+    // Passing NULL as the buffer forces getcwd to allocate
+    // memory for the path, which allows the code to support file paths
+    // longer than _MAX_PATH, which are supported by NTFS.
+    if ((buffer = _getcwd(NULL, 0)) == NULL) {
+        return;
+    }
+    free(buffer);
+}
 
 void validCode()
 {