Prevent infinite loop in ln_var() due to roundoff error.

tglsfdc · tglsfdc · commit 2a1ef30b5779 · 2003-03-14T00:15:32.000Z
Per report from Dave Marin.
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
@@ -5,7 +5,7 @@
  *
  *	1998 Jan Wieck
  *
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/numeric.c,v 1.57 2003/03/11 21:01:33 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/numeric.c,v 1.58 2003/03/14 00:15:32 tgl Exp $
  *
  * ----------
  */
@@ -3872,6 +3872,9 @@ ln_var(NumericVar *arg, NumericVar *result)
 			break;
 
 		add_var(result, &elem, result);
+
+		if (elem.weight < (result->weight - 2 * global_rscale))
+			break;
 	}
 
 	/* Compensate for argument range reduction, round to caller's rscale */

Original file line number	Diff line number	Diff line change
`@@ -5,7 +5,7 @@`
`5`	`5`	`*`
`6`	`6`	`* 1998 Jan Wieck`
`7`	`7`	`*`
`8`		`- * $Header: /cvsroot/pgsql/src/backend/utils/adt/numeric.c,v 1.57 2003/03/11 21:01:33 tgl Exp $`
	`8`	`+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/numeric.c,v 1.58 2003/03/14 00:15:32 tgl Exp $`
`9`	`9`	`*`
`10`	`10`	`* ----------`
`11`	`11`	`*/`
`@@ -3872,6 +3872,9 @@ ln_var(NumericVar arg, NumericVar result)`
`3872`	`3872`	`break;`
`3873`	`3873`
`3874`	`3874`	`add_var(result, &elem, result);`
	`3875`	`+`
	`3876`	`+ if (elem.weight < (result->weight - 2 * global_rscale))`
	`3877`	`+ break;`
`3875`	`3878`	`}`
`3876`	`3879`
`3877`	`3880`	`/* Compensate for argument range reduction, round to caller's rscale */`