1 files changed, 34 insertions, 0 deletions
diff --git a/vendor/curl/src/panic.rs b/vendor/curl/src/panic.rs
new file mode 100644
index 0000000..42cffd8
--- /dev/null
+++ b/vendor/curl/src/panic.rs
@@ -0,0 +1,34 @@
+use std::any::Any;
+use std::cell::RefCell;
+use std::panic::{self, AssertUnwindSafe};
+
+thread_local!(static LAST_ERROR: RefCell<Option<Box<dyn Any + Send>>> = {
+    RefCell::new(None)
+});
+
+pub fn catch<T, F: FnOnce() -> T>(f: F) -> Option<T> {
+    match LAST_ERROR.try_with(|slot| slot.borrow().is_some()) {
+        Ok(true) => return None,
+        Ok(false) => {}
+        // we're in thread shutdown, so we're for sure not panicking and
+        // panicking again will abort, so no need to worry!
+        Err(_) => {}
+    }
+
+    // Note that `AssertUnwindSafe` is used here as we prevent reentering
+    // arbitrary code due to the `LAST_ERROR` check above plus propagation of a
+    // panic after we return back to user code from C.
+    match panic::catch_unwind(AssertUnwindSafe(f)) {
+        Ok(ret) => Some(ret),
+        Err(e) => {
+            LAST_ERROR.with(|slot| *slot.borrow_mut() = Some(e));
+            None
+        }
+    }
+}
+
+pub fn propagate() {
+    if let Ok(Some(t)) = LAST_ERROR.try_with(|slot| slot.borrow_mut().take()) {
+        panic::resume_unwind(t)
+    }
+}