GH-128534: Fix behavior of branch monitoring for `async for` (GH-130847)

* Both branches in a pair now have a common source and are included in co_branches

1 files changed, 5 insertions, 2 deletions

diff --git a/Lib/dis.py b/Lib/dis.py
index 72cc2d19456..c0a25dea2a9 100644
--- a/Lib/dis.py
+++ b/Lib/dis.py
@@ -52,6 +52,7 @@ STORE_FAST_LOAD_FAST = opmap['STORE_FAST_LOAD_FAST']
 STORE_FAST_STORE_FAST = opmap['STORE_FAST_STORE_FAST']
 IS_OP = opmap['IS_OP']
 CONTAINS_OP = opmap['CONTAINS_OP']
+END_ASYNC_FOR = opmap['END_ASYNC_FOR']
 
 CACHE = opmap["CACHE"]
 
@@ -605,7 +606,8 @@ class ArgResolver:
                 argval = self.offset_from_jump_arg(op, arg, offset)
                 lbl = self.get_label_for_offset(argval)
                 assert lbl is not None
-                argrepr = f"to L{lbl}"
+                preposition = "from" if deop == END_ASYNC_FOR else "to"
+                argrepr = f"{preposition} L{lbl}"
             elif deop in (LOAD_FAST_LOAD_FAST, STORE_FAST_LOAD_FAST, STORE_FAST_STORE_FAST):
                 arg1 = arg >> 4
                 arg2 = arg & 15
@@ -745,7 +747,8 @@ def _parse_exception_table(code):
 
 def _is_backward_jump(op):
     return opname[op] in ('JUMP_BACKWARD',
-                          'JUMP_BACKWARD_NO_INTERRUPT')
+                          'JUMP_BACKWARD_NO_INTERRUPT',
+                          'END_ASYNC_FOR') # Not really a jump, but it has a "target"
 
 def _get_instructions_bytes(code, linestarts=None, line_offset=0, co_positions=None,
                             original_code=None, arg_resolver=None):