Credit to OSS-Fuzz: https://bugs.chromium.org/p/oss-fuzz/issues/detai…

…l?id=39555

Comment out bogus code.

xmpsdk/src/XMPUtils.cpp

@@ -175,8 +175,11 @@ static bool
 IsLeapYear ( long year )
 {
 
+// Fix for https://github.com/Exiv2/exiv2/issues/1954:
+// This code looks bogus, and it can also cause an integer overflow, so comment it out.
+#if 0
 	if ( year < 0 ) year = -year + 1;		// Fold the negative years, assuming there is a year 0.
-
+#endif
 	if ( (year % 4) != 0 ) return false;	// Not a multiple of 4.
 	if ( (year % 100) != 0 ) return true;	// A multiple of 4 but not a multiple of 100.
 	if ( (year % 400) == 0 ) return true;	// A multiple of 400.