pythongh-137288: Fix bug where boolean expressions are not associated with the correct exception handler (python#137310)

Author: iritkatriel

Include/internal/pycore_magic_number.h

@@ -281,6 +281,7 @@ Known values:
     Python 3.15a1 3651 (Simplify LOAD_CONST)
     Python 3.15a1 3652 (Virtual iterators)
     Python 3.15a1 3653 (Fix handling of opcodes that may leave operands on the stack when optimizing LOAD_FAST)
+    Python 3.15a1 3654 (Fix missing exception handlers in logical expression)
 
 
     Python 3.16 will start with 3700
@@ -294,7 +295,7 @@ PC/launcher.c must also be updated.
 
 */
 
-#define PYC_MAGIC_NUMBER 3653
+#define PYC_MAGIC_NUMBER 3654
 /* This is equivalent to converting PYC_MAGIC_NUMBER to 2 bytes
    (little-endian) and then appending b'\r\n'. */
 #define PYC_MAGIC_NUMBER_TOKEN \

Lib/test/test_compile.py

@@ -1723,6 +1723,21 @@ def test_compound(self):
         self.assertIs(res, v[3])
         self.assertEqual([e.called for e in v], [1, 1, 0, 1, 0])
 
+    def test_exception(self):
+        # See gh-137288
+        class Foo:
+            def __bool__(self):
+                raise NotImplementedError()
+
+        a = Foo()
+        b = Foo()
+
+        with self.assertRaises(NotImplementedError):
+            bool(a)
+
+        with self.assertRaises(NotImplementedError):
+            c = a or b
+
 @requires_debug_ranges()
 class TestSourcePositions(unittest.TestCase):
     # Ensure that compiled code snippets have correct line and column numbers

Misc/NEWS.d/next/Core_and_Builtins/2025-08-01-18-54-31.gh-issue-137288.FhE7ku.rst

@@ -0,0 +1,2 @@
+Fix bug where some bytecode instructions of a boolean expression are not
+associated with the correct exception handler.

Python/flowgraph.c

@@ -3472,18 +3472,21 @@ convert_pseudo_conditional_jumps(cfg_builder *g)
                 instr->i_opcode = instr->i_opcode == JUMP_IF_FALSE ?
                                           POP_JUMP_IF_FALSE : POP_JUMP_IF_TRUE;
                 location loc = instr->i_loc;
+                basicblock *except = instr->i_except;
                 cfg_instr copy = {
                             .i_opcode = COPY,
                             .i_oparg = 1,
                             .i_loc = loc,
                             .i_target = NULL,
+                            .i_except = except,
                 };
                 RETURN_IF_ERROR(basicblock_insert_instruction(b, i++, &copy));
                 cfg_instr to_bool = {
                             .i_opcode = TO_BOOL,
                             .i_oparg = 0,
                             .i_loc = loc,
                             .i_target = NULL,
+                            .i_except = except,
                 };
                 RETURN_IF_ERROR(basicblock_insert_instruction(b, i++, &to_bool));
             }
@@ -3726,13 +3729,15 @@ insert_prefix_instructions(_PyCompile_CodeUnitMetadata *umd, basicblock *entrybl
             .i_oparg = 0,
             .i_loc = loc,
             .i_target = NULL,
+            .i_except = NULL,
         };
         RETURN_IF_ERROR(basicblock_insert_instruction(entryblock, 0, &make_gen));
         cfg_instr pop_top = {
             .i_opcode = POP_TOP,
             .i_oparg = 0,
             .i_loc = loc,
             .i_target = NULL,
+            .i_except = NULL,
         };
         RETURN_IF_ERROR(basicblock_insert_instruction(entryblock, 1, &pop_top));
     }
@@ -3763,6 +3768,7 @@ insert_prefix_instructions(_PyCompile_CodeUnitMetadata *umd, basicblock *entrybl
                 .i_oparg = oldindex,
                 .i_loc = NO_LOCATION,
                 .i_target = NULL,
+                .i_except = NULL,
             };
             if (basicblock_insert_instruction(entryblock, ncellsused, &make_cell) < 0) {
                 PyMem_RawFree(sorted);
@@ -3779,6 +3785,7 @@ insert_prefix_instructions(_PyCompile_CodeUnitMetadata *umd, basicblock *entrybl
             .i_oparg = nfreevars,
             .i_loc = NO_LOCATION,
             .i_target = NULL,
+            .i_except = NULL,
         };
         RETURN_IF_ERROR(basicblock_insert_instruction(entryblock, 0, &copy_frees));
     }