fix erroneous footer length check in reader

trxcllnt · trxcllnt · commit 85eb7eeece00 · 2018-05-13T16:30:33.000-07:00
diff --git a/js/src/ipc/reader/binary.ts b/js/src/ipc/reader/binary.ts
@@ -162,7 +162,7 @@ function readFileSchema(bb: ByteBuffer) {
         (!checkForMagicArrowString(bb.bytes(), fileLength - magicLength) /* Missing magic end      */) ||
         (/*                                                    Invalid footer length  */
         (footerLength = bb.readInt32(footerOffset = fileLength - magicAndPadding)) < 1 &&
-        (footerLength + magicX2AndPadding > fileLength))) {
+        (footerLength + footerOffset > fileLength))) {
         return null;
     }
     bb.setPosition(footerOffset - footerLength);

Original file line number	Diff line number	Diff line change
`@@ -162,7 +162,7 @@ function readFileSchema(bb: ByteBuffer) {`
`162`	`162`	`(!checkForMagicArrowString(bb.bytes(), fileLength - magicLength) /* Missing magic end */) \|\|`
`163`	`163`	`(/* Invalid footer length */`
`164`	`164`	`(footerLength = bb.readInt32(footerOffset = fileLength - magicAndPadding)) < 1 &&`
`165`		`- (footerLength + magicX2AndPadding > fileLength))) {`
	`165`	`+ (footerLength + footerOffset > fileLength))) {`
`166`	`166`	`return null;`
`167`	`167`	`}`
`168`	`168`	`bb.setPosition(footerOffset - footerLength);`