a while loop can have multiple jump_back's

[rocky]

# Bug in Python 2.7. Bug is bytecode for while loop having
# two consecutive JUMP_BACKS at the end of 'elif' and 'while'
# to the same place
def PreprocessConditionalStatement(self, IfList, ReplacedLine):
    while self:
        if self.__Token:
            x = 1
        elif not IfList:
            if self <= 2:
                continue
            RegionSizeGuid = 3
            if not RegionSizeGuid:
                RegionLayoutLine = 5
                continue
            RegionLayoutLine = self.CurrentLineNumber
    return 1

when compiled and decompiled gives:

$ uncompyle2 bytecode_2.7/05_while_elif.pyc 
# 2019.01.27 21:47:39 EST
#Embedded file name: simple_source/bug27+/05_while_elif.py


def PreprocessConditionalStatement--- This code section failed: ---

0	SETUP_LOOP        '91'
3	LOAD_FAST         'self'
6	POP_JUMP_IF_FALSE '90'

9	LOAD_FAST         'self'
12	LOAD_ATTR         '__Token'
15	POP_JUMP_IF_FALSE '27'

18	LOAD_CONST        1
21	STORE_FAST        'x'
24	JUMP_BACK         '3'

27	LOAD_FAST         'IfList'
30	POP_JUMP_IF_TRUE  '3'

33	LOAD_FAST         'self'
36	LOAD_CONST        2
39	COMPARE_OP        '<='
42_0	COME_FROM         '30'
42	POP_JUMP_IF_FALSE '51'

45	CONTINUE          '3'
48	JUMP_FORWARD      '51'
51_0	COME_FROM         '48'

51	LOAD_CONST        3
54	STORE_FAST        'RegionSizeGuid'

57	LOAD_FAST         'RegionSizeGuid'
60	POP_JUMP_IF_TRUE  '75'

63	LOAD_CONST        5
66	STORE_FAST        'RegionLayoutLine'

69	CONTINUE          '3'
72	JUMP_FORWARD      '75'
75_0	COME_FROM         '72'

75	LOAD_FAST         'self'
78	LOAD_ATTR         'CurrentLineNumber'
81	STORE_FAST        'RegionLayoutLine'
84	JUMP_BACK         '3'
87	JUMP_BACK         '3'
90	POP_BLOCK         None
91_0	COME_FROM         '0'

91	LOAD_CONST        1
94	RETURN_VALUE      None
-1	RETURN_LAST       None

Syntax error at or near `JUMP_BACK' token at offset 87
### Can't uncompyle bytecode_2.7/05_while_elif.pyc
Traceback (most recent call last):
  File "/src/external-vcs/github/uncompyle2-wibiti/uncompyle2/__init__.py", line 197, in main
    uncompyle_file(infile, outstream, showasm, showast, deob)
  File "/src/external-vcs/github/uncompyle2-wibiti/uncompyle2/__init__.py", line 130, in uncompyle_file
    uncompyle(version, co, outstream, showasm, showast, deob)
  File "/src/external-vcs/github/uncompyle2-wibiti/uncompyle2/__init__.py", line 123, in uncompyle
    raise walker.ERROR
ParserError: --- This code section failed: ---

0	SETUP_LOOP        '91'
3	LOAD_FAST         'self'
6	POP_JUMP_IF_FALSE '90'

9	LOAD_FAST         'self'
12	LOAD_ATTR         '__Token'
15	POP_JUMP_IF_FALSE '27'

18	LOAD_CONST        1
21	STORE_FAST        'x'
24	JUMP_BACK         '3'

27	LOAD_FAST         'IfList'
30	POP_JUMP_IF_TRUE  '3'

33	LOAD_FAST         'self'
36	LOAD_CONST        2
39	COMPARE_OP        '<='
42_0	COME_FROM         '30'
42	POP_JUMP_IF_FALSE '51'

45	CONTINUE          '3'
48	JUMP_FORWARD      '51'
51_0	COME_FROM         '48'

51	LOAD_CONST        3
54	STORE_FAST        'RegionSizeGuid'

57	LOAD_FAST         'RegionSizeGuid'
60	POP_JUMP_IF_TRUE  '75'

63	LOAD_CONST        5
66	STORE_FAST        'RegionLayoutLine'

69	CONTINUE          '3'
72	JUMP_FORWARD      '75'
75_0	COME_FROM         '72'

75	LOAD_FAST         'self'
78	LOAD_ATTR         'CurrentLineNumber'
81	STORE_FAST        'RegionLayoutLine'
84	JUMP_BACK         '3'
87	JUMP_BACK         '3'
90	POP_BLOCK         None
91_0	COME_FROM         '0'

91	LOAD_CONST        1
94	RETURN_VALUE      None
-1	RETURN_LAST       None

Syntax error at or near `JUMP_BACK' token at offset 87
# decompiled 0 files: 0 okay, 1 failed, 0 verify failed
# 2019.01.27 21:47:39 EST

rocky/python-uncompyle6@bfceeac can probably be adapted. See also that project for the source file and 2.7 bytecode.