* ext/bigdecimal/bigdecimal.c (BigDecimal_DoDivmod): fix precision.

[ruby-core:17472][ruby-dev:35372][ruby-dev:40105][ruby-dev:40358]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@26626 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Tue Feb  9 23:26:07 2010  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* ext/bigdecimal/bigdecimal.c (BigDecimal_DoDivmod): fix precision.
+	  [ruby-core:17472][ruby-dev:35372][ruby-dev:40105][ruby-dev:40358]
+
 Tue Feb  9 22:23:27 2010  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* io.c (READ_CHECK): do not select fd before reading, that had made

ext/bigdecimal/bigdecimal.c

@@ -970,8 +970,8 @@ BigDecimal_DoDivmod(VALUE self, VALUE r, Real **div, Real **mod)
        return Qtrue;
     }
 
-    mx = a->Prec;
-    if(mx<b->Prec) mx = b->Prec;
+    mx = a->Prec+abs(a->exponent);
+    if(mx<b->Prec+abs(b->exponent)) mx = b->Prec+abs(b->exponent);
     mx =(mx + 1) * VpBaseFig();
     GUARD_OBJ(c,VpCreateRbObject(mx, "0"));
     GUARD_OBJ(res,VpCreateRbObject((mx+1) * 2 +(VpBaseFig() + 1), "#0"));
@@ -983,6 +983,7 @@ BigDecimal_DoDivmod(VALUE self, VALUE r, Real **div, Real **mod)
     VpAddSub(c,a,res,-1);
     if(!VpIsZero(c) && (VpGetSign(a)*VpGetSign(b)<0)) {
         VpAddSub(res,d,VpOne(),-1);
+	GUARD_OBJ(d,VpCreateRbObject(GetAddSubPrec(c, b)*(VpBaseFig() + 1), "0"));
         VpAddSub(d  ,c,b,       1);
         *div = res;
         *mod = d;