Avoid integer overflow when LIMIT + OFFSET >= 2^63.

hlinnaka · hlinnaka · commit 443a44ba62c3 · 2011-08-02T11:31:55.000+03:00
This fixes bug #6139 reported by Hitoshi Harada.
diff --git a/src/backend/executor/nodeLimit.c b/src/backend/executor/nodeLimit.c
@@ -120,7 +120,7 @@ ExecLimit(LimitState *node)
 				 * the state machine state to record having done so.
 				 */
 				if (!node->noCount &&
-					node->position >= node->offset + node->count)
+					node->position - node->offset >= node->count)
 				{
 					node->lstate = LIMIT_WINDOWEND;
 					return NULL;

Original file line number	Diff line number	Diff line change
`@@ -120,7 +120,7 @@ ExecLimit(LimitState *node)`
`120`	`120`	`* the state machine state to record having done so.`
`121`	`121`	`*/`
`122`	`122`	`if (!node->noCount &&`
`123`		`- node->position >= node->offset + node->count)`
	`123`	`+ node->position - node->offset >= node->count)`
`124`	`124`	`{`
`125`	`125`	`node->lstate = LIMIT_WINDOWEND;`
`126`	`126`	`return NULL;`