defs: Define magic "unknown_color" (-1).

diff --git a/defs.h b/defs.h
index 03c2ec2dfdee3a4ba173444a1ecd1cca26bb7574..d96dfda3dffb86efcc304bb2585d0dd35d8c9e2e 100644 (file)
--- a/defs.h
+++ b/defs.h
@@ -999,5 +999,6 @@ int color_to_bbggrr(char *cname);
  * but that's not very nice for the folks near sea level.
  */
 #define unknown_alt    -99999999.0
+#define unknown_color  -1
 
 #endif /* gpsbabel_defs_h_included */