1 files changed, 29 insertions, 27 deletions

diff --git a/math.c b/math.c
index 4cdcbc7471..259d4c91df 100644
--- a/math.c
+++ b/math.c
@@ -22,6 +22,27 @@ VALUE rb_mMath;
     Need_Float(y);\
 } while (0)
 
+static void
+domain_check(x, msg)
+    double x;
+    char *msg;
+{
+    while(1) {
+	if (errno) {
+	    rb_sys_fail(msg);
+	}
+	if (isnan(x)) {
+#if defined(EDOM)
+	    errno = EDOM;
+#elif define(ERANGE)
+	    errno = ERANGE;
+#endif
+	    continue;
+	}
+	break;
+    }
+}
+
 
 /*
  *  call-seq:
@@ -40,7 +61,6 @@ math_atan2(VALUE obj, VALUE y, VALUE x)
 }
 
 
-
 /*
  *  call-seq:
  *     Math.cos(x)    => float
@@ -103,9 +123,7 @@ math_acos(VALUE obj, VALUE x)
     Need_Float(x);
     errno = 0;
     d = acos(RFLOAT(x)->value);
-    if (errno) {
-	rb_sys_fail("acos");
-    }
+    domain_check(d, "acos");
     return rb_float_new(d);
 }
 
@@ -124,9 +142,7 @@ math_asin(VALUE obj, VALUE x)
     Need_Float(x);
     errno = 0;
     d = asin(RFLOAT(x)->value);
-    if (errno) {
-	rb_sys_fail("asin");
-    }
+    domain_check(d, "asin");
     return rb_float_new(d);
 }
 
@@ -228,9 +244,7 @@ math_acosh(VALUE obj, VALUE x)
     Need_Float(x);
     errno = 0;
     d = acosh(RFLOAT(x)->value);
-    if (errno) {
-	rb_sys_fail("acosh");
-    }
+    domain_check(d, "acosh");
     return rb_float_new(d);
 }
 
@@ -263,9 +277,7 @@ math_atanh(VALUE obj, VALUE x)
     Need_Float(x);
     errno = 0;
     d = atanh(RFLOAT(x)->value);
-    if (errno) {
-	rb_sys_fail("atanh");
-    }
+    domain_check(d, "atanh");
     return rb_float_new(d);
 }
 
@@ -309,16 +321,11 @@ math_log(int argc, VALUE *argv)
     Need_Float(x);
     errno = 0;
     d = log(RFLOAT(x)->value);
-    if (errno) {
-	rb_sys_fail("log");
-    }
     if (!NIL_P(base)) {
 	Need_Float(base);
 	d /= log(RFLOAT(base)->value);
     }
-    if (errno) {
-	rb_sys_fail("log");
-    }
+    domain_check(d);
     return rb_float_new(d);
 }
 
@@ -370,9 +377,7 @@ math_log10(VALUE obj, VALUE x)
     Need_Float(x);
     errno = 0;
     d = log10(RFLOAT(x)->value);
-    if (errno) {
-	rb_sys_fail("log10");
-    }
+    domain_check(d, "log10");
     return rb_float_new(d);
 }
 
@@ -380,8 +385,7 @@ math_log10(VALUE obj, VALUE x)
  *  call-seq:
  *     Math.sqrt(numeric)    => float
  *  
- *  Returns the non-negative square root of <i>numeric</i>. Raises
- *  <code>ArgError</code> if <i>numeric</i> is less than zero.
+ *  Returns the non-negative square root of <i>numeric</i>.
  */
 
 static VALUE
@@ -392,9 +396,7 @@ math_sqrt(VALUE obj, VALUE x)
     Need_Float(x);
     errno = 0;
     d = sqrt(RFLOAT(x)->value);
-    if (errno) {
-	rb_sys_fail("sqrt");
-    }
+    domain_check(d, "sqrt");
     return rb_float_new(d);
 }