shithub: libmujs

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Fix Math.atan2 and Math.pow argument evaluation order

Math.pow has subtly different semantics than ISO C pow for the
non-finite powers of +-1, so that's handled separately.
(ECMA requires NAN result, in ISO C Annex F pow(1,any) == 1 and
pow(-1,+-inf) == 1)

--- a/jsmath.c

+++ b/jsmath.c

@@ -24,7 +24,9 @@

 static void Math_atan2(js_State *J)

 {

-	js_pushnumber(J, atan2(js_tonumber(J, 1), js_tonumber(J, 2)));

+	double y = js_tonumber(J, 1);

+	double x = js_tonumber(J, 2);

+	js_pushnumber(J, atan2(y, x));

 }

 static void Math_ceil(js_State *J)

@@ -54,7 +56,12 @@

 static void Math_pow(js_State *J)

 {

-	js_pushnumber(J, pow(js_tonumber(J, 1), js_tonumber(J, 2)));

+	double x = js_tonumber(J, 1);

+	double y = js_tonumber(J, 2);

+	if (!isfinite(y) && fabs(x) == 1)

+		js_pushnumber(J, NAN);

+	else

+		js_pushnumber(J, pow(x,y));

 }

 static void Math_random(js_State *J)