explain what happens in a test

RalfJung · RalfJung · commit ff1f0b06cca7 · 2020-05-03T12:43:38.000+02:00
diff --git a/tests/run-pass/transmute_fat2.rs b/tests/run-pass/transmute_fat2.rs
@@ -8,5 +8,6 @@ fn main() {
     let bad = unsafe {
         std::mem::transmute::<u64, &[u8]>(42)
     };
+    // This created a slice with length 0, so the following will fail the bounds check.
     bad[0];
 }
diff --git a/tests/run-pass/transmute_fat2.stderr b/tests/run-pass/transmute_fat2.stderr
@@ -1 +1 @@
-thread 'main' panicked at 'index out of bounds: the len is 0 but the index is 0', $DIR/transmute_fat2.rs:11:5
+thread 'main' panicked at 'index out of bounds: the len is 0 but the index is 0', $DIR/transmute_fat2.rs:12:5

Original file line number	Diff line number	Diff line change
`@@ -8,5 +8,6 @@ fn main() {`
`8`	`8`	`let bad = unsafe {`
`9`	`9`	`std::mem::transmute::<u64, &[u8]>(42)`
`10`	`10`	`};`
	`11`	`+ // This created a slice with length 0, so the following will fail the bounds check.`
`11`	`12`	`bad[0];`
`12`	`13`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-thread 'main' panicked at 'index out of bounds: the len is 0 but the index is 0', $DIR/transmute_fat2.rs:11:5`
	`1`	`+thread 'main' panicked at 'index out of bounds: the len is 0 but the index is 0', $DIR/transmute_fat2.rs:12:5`