test/test_mixramp: improved test for mixramp_interpolate(0)

test/test_mixramp.cxx

@@ -22,7 +22,9 @@ public:
 		const char *input = "1.0 0.00;3.0 0.10;6.0 2.50;";
 
 		char *foo = strdup(input);
-		CPPUNIT_ASSERT(!std::isnan(mixramp_interpolate(foo, 0)));
+		CPPUNIT_ASSERT_DOUBLES_EQUAL(double(0),
+					     mixramp_interpolate(foo, 0),
+					     0.05);
 		free(foo);
 
 		foo = strdup(input);
@@ -41,10 +43,6 @@ public:
 		free(foo);
 
 		foo = strdup(input);
-		CPPUNIT_ASSERT(!std::isnan(mixramp_interpolate(foo, 3)));
-		free(foo);
-
-		foo = strdup(input);
 		CPPUNIT_ASSERT(std::isnan(mixramp_interpolate(foo, 6.1)));
 		free(foo);