templater: parse \"...\" as string for 2.9.2-3.4 compatibility (issue4733)
As of Mercurial 3.4, there were several syntax rules to process nested
template strings. Unfortunately, they were inconsistent and conflicted
each other.
a. buildmap() rule
- template string is _parsed_ as string, and parsed as template
- <\"> is not allowed in nested template:
{xs % "{f(\"{x}\")}"} -> parse error
- template escaping <\{> is handled consistently:
{xs % "\{x}"} -> escaped
b. _evalifliteral() rule
- template string is _interpreted_ as string, and parsed as template
in crafted environment to avoid double processing of escape sequences
- <\"> is allowed in nested template:
{if(x, "{f(\"{x}\")}")}
- <\{> and escape sequences in string literal in nested template are not
handled well
c. pad() rule
- template string is first interpreted as string, and parsed as template,
which means escape sequences are processed twice
- <\"> is allowed in nested template:
{pad("{xs % \"{x}\"}', 10)}
Because of the issue of template escaping, issue4714, 7298da81f5a9 (in stable)
unified the rule (b) to (a). Then, 576d6c74784b (in default) unified the rule
(c) to (b) = (a). But they disabled the following syntax that was somewhat
considered valid.
{if(rev, "{if(rev, \"{rev}\")}")}
{pad("{files % \"{file}\"}", 10)}
So, this patch introduces \"...\" literal to work around the escaped-quoted
nested template strings. Because this parsing rule exists only for the backward
compatibility, it is designed to copy the behavior of old _evalifliteral() as
possible.
Future patches will introduce a better parsing rule similar to a command
substitution of POSIX shells or a string interpolation of Ruby, where extra
escapes won't be necessary at all.
{pad("{files % "{file}"}", 10)}
~~~~~~~~~~~~~~~~~~
parsed as a template, not as a string
Because <\> character wasn't allowed in a template fragment, this patch won't
introduce more breakages. But the syntax of nested templates are interpreted
differently by people, there might be unknown issues. So if we want, we could
instead remove db7463aa080f, 890845af1ac2 and 7298da81f5a9 from the stable
branch as the bug fixed by these patches existed for longer periods.
554d6fcc3c8, "strip single backslash before quotation mark in quoted template",
should be superseded by this patch. I'll remove it later.
# fancyopts.py - better command line parsing
#
# Copyright 2005-2009 Matt Mackall <mpm@selenic.com> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import getopt
import util
from i18n import _
def gnugetopt(args, options, longoptions):
"""Parse options mostly like getopt.gnu_getopt.
This is different from getopt.gnu_getopt in that an argument of - will
become an argument of - instead of vanishing completely.
"""
extraargs = []
if '--' in args:
stopindex = args.index('--')
extraargs = args[stopindex + 1:]
args = args[:stopindex]
opts, parseargs = getopt.getopt(args, options, longoptions)
args = []
while parseargs:
arg = parseargs.pop(0)
if arg and arg[0] == '-' and len(arg) > 1:
parseargs.insert(0, arg)
topts, newparseargs = getopt.getopt(parseargs, options, longoptions)
opts = opts + topts
parseargs = newparseargs
else:
args.append(arg)
args.extend(extraargs)
return opts, args
def fancyopts(args, options, state, gnu=False):
"""
read args, parse options, and store options in state
each option is a tuple of:
short option or ''
long option
default value
description
option value label(optional)
option types include:
boolean or none - option sets variable in state to true
string - parameter string is stored in state
list - parameter string is added to a list
integer - parameter strings is stored as int
function - call function with parameter
non-option args are returned
"""
namelist = []
shortlist = ''
argmap = {}
defmap = {}
for option in options:
if len(option) == 5:
short, name, default, comment, dummy = option
else:
short, name, default, comment = option
# convert opts to getopt format
oname = name
name = name.replace('-', '_')
argmap['-' + short] = argmap['--' + oname] = name
defmap[name] = default
# copy defaults to state
if isinstance(default, list):
state[name] = default[:]
elif callable(default):
state[name] = None
else:
state[name] = default
# does it take a parameter?
if not (default is None or default is True or default is False):
if short:
short += ':'
if oname:
oname += '='
if short:
shortlist += short
if name:
namelist.append(oname)
# parse arguments
if gnu:
parse = gnugetopt
else:
parse = getopt.getopt
opts, args = parse(args, shortlist, namelist)
# transfer result to state
for opt, val in opts:
name = argmap[opt]
t = type(defmap[name])
if t is type(fancyopts):
state[name] = defmap[name](val)
elif t is type(1):
try:
state[name] = int(val)
except ValueError:
raise util.Abort(_('invalid value %r for option %s, '
'expected int') % (val, opt))
elif t is type(''):
state[name] = val
elif t is type([]):
state[name].append(val)
elif t is type(None) or t is type(False):
state[name] = True
# return unparsed args
return args