make sure reads fit file bounds

mafintosh · mafintosh · commit 33d3ee0006fb · 2018-08-23T02:38:52.000+02:00
diff --git a/index.js b/index.js
@@ -106,9 +106,12 @@ function createFile (name, opts) {
   }
 
   function read (req) {
+    const end = req.offset + req.size
+    if (end > file.size) return req.callback(new Error('Could not satisfy length'))
+
     const io = readers.pop() || allocReader()
     io.req = req
-    io.reader.readAsArrayBuffer(file.slice(req.offset, req.offset + req.size))
+    io.reader.readAsArrayBuffer(file.slice(req.offset, end))
   }
 
   function close (req) {

Original file line number	Diff line number	Diff line change
`@@ -106,9 +106,12 @@ function createFile (name, opts) {`
`106`	`106`	`}`
`107`	`107`
`108`	`108`	`function read (req) {`
	`109`	`+ const end = req.offset + req.size`
	`110`	`+ if (end > file.size) return req.callback(new Error('Could not satisfy length'))`
	`111`	`+`
`109`	`112`	`const io = readers.pop() \|\| allocReader()`
`110`	`113`	`io.req = req`
`111`		`- io.reader.readAsArrayBuffer(file.slice(req.offset, req.offset + req.size))`
	`114`	`+ io.reader.readAsArrayBuffer(file.slice(req.offset, end))`
`112`	`115`	`}`
`113`	`116`
`114`	`117`	`function close (req) {`