Panic on integer overflow in Chain::remaining (#482)

stepancheg · web-flow · commit 2428c152a67c · 2021-02-16T12:44:33.000-08:00
Make it safer.
diff --git a/src/buf/chain.rs b/src/buf/chain.rs
@@ -135,7 +135,7 @@ where
     U: Buf,
 {
     fn remaining(&self) -> usize {
-        self.a.remaining() + self.b.remaining()
+        self.a.remaining().checked_add(self.b.remaining()).unwrap()
     }
 
     fn chunk(&self) -> &[u8] {
@@ -178,7 +178,10 @@ where
     U: BufMut,
 {
     fn remaining_mut(&self) -> usize {
-        self.a.remaining_mut() + self.b.remaining_mut()
+        self.a
+            .remaining_mut()
+            .checked_add(self.b.remaining_mut())
+            .unwrap()
     }
 
     fn chunk_mut(&mut self) -> &mut UninitSlice {

Original file line number	Diff line number	Diff line change
`@@ -135,7 +135,7 @@ where`
`135`	`135`	`U: Buf,`
`136`	`136`	`{`
`137`	`137`	`fn remaining(&self) -> usize {`
`138`		`- self.a.remaining() + self.b.remaining()`
	`138`	`+ self.a.remaining().checked_add(self.b.remaining()).unwrap()`
`139`	`139`	`}`
`140`	`140`
`141`	`141`	`fn chunk(&self) -> &[u8] {`
`@@ -178,7 +178,10 @@ where`
`178`	`178`	`U: BufMut,`
`179`	`179`	`{`
`180`	`180`	`fn remaining_mut(&self) -> usize {`
`181`		`- self.a.remaining_mut() + self.b.remaining_mut()`
	`181`	`+ self.a`
	`182`	`+ .remaining_mut()`
	`183`	`+ .checked_add(self.b.remaining_mut())`
	`184`	`+ .unwrap()`
`182`	`185`	`}`
`183`	`186`
`184`	`187`	`fn chunk_mut(&mut self) -> &mut UninitSlice {`