auto merge of #8581 : FlaPer87/rust/issue/8232, r=bblum

As for now, rekillable is an unsafe function, instead, it should behave
just like unkillable by encapsulating unsafe code within an unsafe
block.

This patch does that and removes unsafe blocks that were encapsulating
rekillable calls throughout rust's libs.

Fixes #8232

1 files changed, 5 insertions, 1 deletions

diff --git a/src/libstd/rt/kill.rs b/src/libstd/rt/kill.rs
index b0b425e3aee..94df621ce76 100644
--- a/src/libstd/rt/kill.rs
+++ b/src/libstd/rt/kill.rs
@@ -647,7 +647,11 @@ impl Death {
     /// All calls must be paired with a preceding call to inhibit_kill.
     #[inline]
     pub fn allow_kill(&mut self, already_failing: bool) {
-        rtassert!(self.unkillable != 0);
+        if self.unkillable == 0 {
+            // we need to decrement the counter before failing.
+            self.unkillable -= 1;
+            fail!("Cannot enter a rekillable() block without a surrounding unkillable()");
+        }
         self.unkillable -= 1;
         if self.unkillable == 0 {
             rtassert!(self.kill_handle.is_some());