do vs2017 warnings.h a little differently than vs2019

fixes #545

include/warnings.h

@@ -68,6 +68,7 @@
 #define STDC_Pragma_AVAILABLE
 
 #elif defined(_MSC_VER)
+#if _MSC_VER > 1916
 #define DISABLE_WARNING_UNREACHABLE_CODE \
                            _Pragma("warning( push )") \
                            _Pragma("warning( disable : 4702 )")
@@ -81,6 +82,21 @@
 #define RESTORE_WARNING_FORMAT_NONLITERAL _Pragma("warning( pop )")
 #define RESTORE_WARNINGS _Pragma("warning( pop )")
 #define STDC_Pragma_AVAILABLE
+#else  /* Visual Studio prior to 2019 below */
+#define DISABLE_WARNING_UNREACHABLE_CODE \
+                           __pragma(warning(push)) \
+                           __pragma(warning(disable:4702))
+#define DISABLE_WARNING_FORMAT_NONLITERAL \
+                           __pragma(warning(push)) \
+                           __pragma(warning(disable:4774))
+#define DISABLE_WARNING_CONDEXPR_IS_CONSTANT \
+                           __pragma(warning(push)) \
+                           __pragma(warning(disable:4127))
+#define RESTORE_WARNING_CONDEXPR_IS_CONSTANT __pragma(warning(pop))
+#define RESTORE_WARNING_FORMAT_NONLITERAL __pragma(warning(pop))
+#define RESTORE_WARNINGS  __pragma(warning(pop))
+#define STDC_Pragma_AVAILABLE
+#endif /* vs2019 or vs2017 */
 
 #endif /* various compiler detections */
 #endif /* ACTIVATE_WARNING_PRAGMAS */

sys/windows/consoletty.c

@@ -1899,11 +1899,10 @@ void nethack_enter_consoletty()
 
     /* grow the size of the console buffer if it is not wide enough */
     if (console.origcsbi.dwSize.X < console.width) {
-        COORD screen_size = {
+        COORD screen_size = {0};
-            screen_size.Y = console.origcsbi.dwSize.Y,
-            screen_size.X = console.width
-        };
 
+        screen_size.Y = console.origcsbi.dwSize.Y,
+        screen_size.X = console.width;
         SetConsoleScreenBufferSize(console.hConOut, screen_size);
     }
 

win/win32/mhmap.c

@@ -965,8 +965,11 @@ paintGlyph(PNHMapWindow data, int i, int j, RECT * rect)
                 DeleteObject(brush);
                 intensity = (wch == 0x2591 ? 100 : 200);
                 brush = CreateSolidBrush(RGB(intensity, intensity, intensity));
-                RECT smallRect = { rect->left + 1, rect->top + 1,
+                RECT smallRect = {0};
-                                    rect->right - 1, rect->bottom - 1 };
+                smallRect.left = rect->left + 1;
+                smallRect.top = rect->top + 1;
+                smallRect.right = rect->right - 1;
+                smallRect.bottom = rect->bottom - 1;
                 FillRect(data->backBufferDC, &smallRect, brush);
                 DeleteObject(brush);
             } else {