Merge pull request RustPython#3710 from youknowone/fix-hash

youknowone · web-flow · commit 44ccc4015fdb · 2022-05-17T06:19:04.000+09:00
Fix lcg_random overflow
diff --git a/common/src/hash.rs b/common/src/hash.rs
@@ -186,8 +186,8 @@ pub fn mod_int(value: i64) -> PyHash {
 
 pub fn lcg_urandom(mut x: u32, buf: &mut [u8]) {
     for b in buf {
-        x *= 214013;
-        x += 2531011;
+        x = x.wrapping_mul(214013);
+        x = x.wrapping_add(2531011);
         *b = ((x >> 16) & 0xff) as u8;
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -186,8 +186,8 @@ pub fn mod_int(value: i64) -> PyHash {`
`186`	`186`
`187`	`187`	`pub fn lcg_urandom(mut x: u32, buf: &mut [u8]) {`
`188`	`188`	`for b in buf {`
`189`		`- x *= 214013;`
`190`		`- x += 2531011;`
	`189`	`+ x = x.wrapping_mul(214013);`
	`190`	`+ x = x.wrapping_add(2531011);`
`191`	`191`	`*b = ((x >> 16) & 0xff) as u8;`
`192`	`192`	`}`
`193`	`193`	`}`