raise proper error for negative values in _PyLong_AsByteArray

Author: lukasstadler

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/cext/PythonCextLongBuiltins.java

@@ -420,6 +420,9 @@ static Object get(int value, Object bytes, long n, int littleEndian, int isSigne
                         @Shared @Cached InlinedConditionProfile profile,
                         @Shared @Cached PRaiseNode raise,
                         @Shared @Cached CStructAccess.WriteByteNode write) {
+            if (isSigned == 0 && value < 0) {
+                throw raise.raise(OverflowError, ErrorMessages.MESSAGE_CONVERT_NEGATIVE);
+            }
 
             byte[] array = IntBuiltins.ToBytesNode.fromLong(value, PythonUtils.toIntError(n), littleEndian == 0, isSigned != 0, inliningTarget, profile, raise);
             write.writeByteArray(bytes, array);
@@ -432,6 +435,9 @@ static Object get(long value, Object bytes, long n, int littleEndian, int isSign
                         @Shared @Cached InlinedConditionProfile profile,
                         @Shared @Cached PRaiseNode raise,
                         @Shared @Cached CStructAccess.WriteByteNode write) {
+            if (isSigned == 0 && value < 0) {
+                throw raise.raise(OverflowError, ErrorMessages.MESSAGE_CONVERT_NEGATIVE);
+            }
 
             byte[] array = IntBuiltins.ToBytesNode.fromLong(value, PythonUtils.toIntError(n), littleEndian == 0, isSigned != 0, inliningTarget, profile, raise);
             write.writeByteArray(bytes, array);
@@ -444,6 +450,9 @@ static Object get(PInt value, Object bytes, long n, int littleEndian, int isSign
                         @Shared @Cached InlinedConditionProfile profile,
                         @Shared @Cached PRaiseNode raise,
                         @Shared @Cached CStructAccess.WriteByteNode write) {
+            if (isSigned == 0 && value.isNegative()) {
+                throw raise.raise(OverflowError, ErrorMessages.MESSAGE_CONVERT_NEGATIVE);
+            }
 
             byte[] array = IntBuiltins.ToBytesNode.fromBigInteger(value, PythonUtils.toIntError(n), littleEndian == 0, isSigned != 0, inliningTarget, profile, raise);
             write.writeByteArray(bytes, array);