Use memmove() rather than memcpy() in set_var_from_var(). If this function

Neil Conway · Neil Conway · commit e66fcce67272 · 2004-02-04T01:11:47.000Z
is asked to assign a variable to itself, it will result in doing a
memcpy() on an entirely-overlapping memory range, which results in
undefined behavior according to ANSI C. That said, it is unlikely to
actually do anything bad on any sane libc, but this keeps valgrind quiet.
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
@@ -14,7 +14,7 @@
  * Copyright (c) 1998-2003, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.70 2003/12/02 00:26:59 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.71 2004/02/04 01:11:47 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2729,7 +2729,7 @@ set_var_from_var(NumericVar *value, NumericVar *dest)
 
 	digitbuf_free(dest->buf);
 
-	memcpy(dest, value, sizeof(NumericVar));
+	memmove(dest, value, sizeof(NumericVar));
 	dest->buf = newbuf;
 	dest->digits = newbuf + 1;
 }

Original file line number	Diff line number	Diff line change
`@@ -14,7 +14,7 @@`
`14`	`14`	`* Copyright (c) 1998-2003, PostgreSQL Global Development Group`
`15`	`15`	`*`
`16`	`16`	`* IDENTIFICATION`
`17`		`- * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.70 2003/12/02 00:26:59 tgl Exp $`
	`17`	`+ * $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.71 2004/02/04 01:11:47 neilc Exp $`
`18`	`18`	`*`
`19`	`19`	`*-------------------------------------------------------------------------`
`20`	`20`	`*/`
`@@ -2729,7 +2729,7 @@ set_var_from_var(NumericVar value, NumericVar dest)`
`2729`	`2729`
`2730`	`2730`	`digitbuf_free(dest->buf);`
`2731`	`2731`
`2732`		`- memcpy(dest, value, sizeof(NumericVar));`
	`2732`	`+ memmove(dest, value, sizeof(NumericVar));`
`2733`	`2733`	`dest->buf = newbuf;`
`2734`	`2734`	`dest->digits = newbuf + 1;`
`2735`	`2735`	`}`