py: Reraising exception possible only in except block.

2 files changed, 11 insertions, 1 deletions

diff --git a/py/vm.c b/py/vm.c
index f340f5219..d28416db3 100644
--- a/py/vm.c
+++ b/py/vm.c
@@ -697,6 +697,9 @@ unwind_return:
                         unum = *ip++;
                         assert(unum <= 1);
                         if (unum == 0) {
+                            if (!currently_in_except_block) {
+                                nlr_jump(mp_obj_new_exception_msg(&mp_type_RuntimeError, "No active exception to reraise"));
+                            }
                             // This assumes that nlr.ret_val holds last raised
                             // exception and is not overwritten since then.
                             obj1 = nlr.ret_val;
diff --git a/tests/basics/try-reraise.py b/tests/basics/try-reraise.py
index bc817fc38..bf5e77c0b 100644
--- a/tests/basics/try-reraise.py
+++ b/tests/basics/try-reraise.py
@@ -1,4 +1,4 @@
-# Re-reraising last exception with raise w/o args
+# Reraising last exception with raise w/o args
 
 def f():
     try:
@@ -10,3 +10,10 @@ try:
     f()
 except ValueError as e:
     print(repr(e))
+
+
+# Can reraise only in except block
+try:
+    raise
+except RuntimeError:
+    print("RuntimeError")