gh-148278: Fix try except block bug

Lib/test/test_compile.py

@@ -1633,6 +1633,56 @@ def test_remove_redundant_nop_edge_case(self):
         def f():
             a if (1 if b else c) else d
 
+    def test_while_continue_try_except_exception_table(self):
+        # The try region's exception table must include the backward jump emitted
+        # for 'continue', so pending exceptions (e.g. KeyboardInterrupt) and
+        # tracing behave like other try-body instructions.
+        src = textwrap.dedent('''\
+            def f():
+                while True:
+                    try:
+                        continue
+                    except KeyboardInterrupt:
+                        break
+        ''')
+        f_code = compile(src, '<string>', 'exec').co_consts[0]
+        jump_offsets = [
+            i.offset for i in dis.get_instructions(f_code)
+            if i.opname == 'JUMP_BACKWARD'
+        ]
+        self.assertEqual(len(jump_offsets), 1)
+        joff = jump_offsets[0]
+        entries = dis._parse_exception_table(f_code)
+        self.assertTrue(
+            any(e.start <= joff < e.end for e in entries),
+            f'offset {joff} not covered by {entries!r}',
+        )
+
+    def test_try_literal_stmt_exception_table(self):
+        # Like try + continue, a try body that is only a literal statement must
+        # not leave the "invisible" result-discard outside the exception table.
+        src = textwrap.dedent('''\
+            def f():
+                try:
+                    42
+                except:
+                    pass
+        ''')
+        f_code = compile(src, '<string>', 'exec').co_consts[0]
+        body_offsets = [
+            i.offset for i in dis.get_instructions(f_code)
+            if i.positions is not None
+            and i.positions.lineno == 3
+            and i.opname not in ('RESUME', 'NOP')
+        ]
+        self.assertNotEqual(body_offsets, [])
+        entries = dis._parse_exception_table(f_code)
+        for off in body_offsets:
+            self.assertTrue(
+                any(e.start <= off < e.end for e in entries),
+                f'offset {off} not covered by {entries!r}',
+            )
+
     def test_lineno_propagation_empty_blocks(self):
         # Smoke test. See gh-138714.
         def f():

Misc/NEWS.d/next/Core_and_Builtins/2026-04-10-12-00-00.gh-issue-148278.4Kp9mN.rst

@@ -0,0 +1,4 @@
+Fix exception table coverage for ``try`` blocks: pseudo ``SETUP_FINALLY`` and
+``POP_BLOCK`` instructions are now labeled with the active handler, so
+``continue`` inside ``try``/``except`` and other minimal try bodies handle
+pending exceptions and tracing like the rest of the protected region.

Python/flowgraph.c

@@ -932,8 +932,17 @@ label_exception_targets(basicblock *entryblock) {
                     todo++;
                 }
                 handler = push_except_block(except_stack, instr);
+                /* Exception coverage for this instruction must match the try
+                 * region it opens, so tracing and pending exceptions while
+                 * executing it are handled like the following protected
+                 * instructions. */
+                instr->i_except = handler;
             }
             else if (instr->i_opcode == POP_BLOCK) {
+                /* POP_BLOCK ends a protected region but must still be covered by
+                 * that region's handler until the pop completes (e.g. continue
+                 * inside try). */
+                instr->i_except = except_stack_top(except_stack);
                 handler = pop_except_block(except_stack);
                 INSTR_SET_OP0(instr, NOP);
             }