solaris: tests can't use tail -n

Solaris tail doesn't recognize the -n option.  Replace the one use of it
with some inline python code, and add a test case to check-code.py.

contrib/check-code.py

@@ -1,521 +1,522 b''
 #!/usr/bin/env python
 #
 # check-code - a style and portability checker for Mercurial
 #
 # Copyright 2010 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 import re, glob, os, sys
 import keyword
 import optparse
 try:
     import re2
 except ImportError:
     re2 = None
 
 def compilere(pat, multiline=False):
     if multiline:
         pat = '(?m)' + pat
     if re2:
         try:
             return re2.compile(pat)
         except re2.error:
             pass
     return re.compile(pat)
 
 def repquote(m):
     t = re.sub(r"\w", "x", m.group('text'))
     t = re.sub(r"[^\s\nx]", "o", t)
     return m.group('quote') + t + m.group('quote')
 
 def reppython(m):
     comment = m.group('comment')
     if comment:
         l = len(comment.rstrip())
         return "#" * l + comment[l:]
     return repquote(m)
 
 def repcomment(m):
     return m.group(1) + "#" * len(m.group(2))
 
 def repccomment(m):
     t = re.sub(r"((?<=\n) )|\S", "x", m.group(2))
     return m.group(1) + t + "*/"
 
 def repcallspaces(m):
     t = re.sub(r"\n\s+", "\n", m.group(2))
     return m.group(1) + t
 
 def repinclude(m):
     return m.group(1) + "<foo>"
 
 def rephere(m):
     t = re.sub(r"\S", "x", m.group(2))
     return m.group(1) + t
 
 
 testpats = [
   [
     (r'pushd|popd', "don't use 'pushd' or 'popd', use 'cd'"),
     (r'\W\$?\(\([^\)\n]*\)\)', "don't use (()) or $(()), use 'expr'"),
     (r'grep.*-q', "don't use 'grep -q', redirect to /dev/null"),
     (r'(?<!hg )grep.*-a', "don't use 'grep -a', use in-line python"),
     (r'sed.*-i', "don't use 'sed -i', use a temporary file"),
     (r'\becho\b.*\\n', "don't use 'echo \\n', use printf"),
     (r'echo -n', "don't use 'echo -n', use printf"),
     (r'(^| )wc[^|]*$\n(?!.*\(re\))', "filter wc output"),
     (r'head -c', "don't use 'head -c', use 'dd'"),
+    (r'tail -n', "don't use the '-n' option to tail, just use '-<num>'"),
     (r'sha1sum', "don't use sha1sum, use $TESTDIR/md5sum.py"),
     (r'ls.*-\w*R', "don't use 'ls -R', use 'find'"),
     (r'printf.*[^\\]\\([1-9]|0\d)', "don't use 'printf \NNN', use Python"),
     (r'printf.*[^\\]\\x', "don't use printf \\x, use Python"),
     (r'\$\(.*\)', "don't use $(expr), use `expr`"),
     (r'rm -rf \*', "don't use naked rm -rf, target a directory"),
     (r'(^|\|\s*)grep (-\w\s+)*[^|]*[(|]\w',
      "use egrep for extended grep syntax"),
     (r'/bin/', "don't use explicit paths for tools"),
     (r'[^\n]\Z', "no trailing newline"),
     (r'export.*=', "don't export and assign at once"),
     (r'^source\b', "don't use 'source', use '.'"),
     (r'touch -d', "don't use 'touch -d', use 'touch -t' instead"),
     (r'ls +[^|\n-]+ +-', "options to 'ls' must come before filenames"),
     (r'[^>\n]>\s*\$HGRCPATH', "don't overwrite $HGRCPATH, append to it"),
     (r'^stop\(\)', "don't use 'stop' as a shell function name"),
     (r'(\[|\btest\b).*-e ', "don't use 'test -e', use 'test -f'"),
     (r'^alias\b.*=', "don't use alias, use a function"),
     (r'if\s*!', "don't use '!' to negate exit status"),
     (r'/dev/u?random', "don't use entropy, use /dev/zero"),
     (r'do\s*true;\s*done', "don't use true as loop body, use sleep 0"),
     (r'^( *)\t', "don't use tabs to indent"),
     (r'sed (-e )?\'(\d+|/[^/]*/)i(?!\\\n)',
      "put a backslash-escaped newline after sed 'i' command"),
   ],
   # warnings
   [
     (r'^function', "don't use 'function', use old style"),
     (r'^diff.*-\w*N', "don't use 'diff -N'"),
     (r'\$PWD|\${PWD}', "don't use $PWD, use `pwd`"),
     (r'^([^"\'\n]|("[^"\n]*")|(\'[^\'\n]*\'))*\^', "^ must be quoted"),
     (r'kill (`|\$\()', "don't use kill, use killdaemons.py")
   ]
 ]
 
 testfilters = [
     (r"( *)(#([^\n]*\S)?)", repcomment),
     (r"<<(\S+)((.|\n)*?\n\1)", rephere),
 ]
 
 winglobmsg = "use (glob) to match Windows paths too"
 uprefix = r"^  \$ "
 utestpats = [
   [
     (r'^(\S.*||  [$>] .*)[ \t]\n', "trailing whitespace on non-output"),
     (uprefix + r'.*\|\s*sed[^|>\n]*\n',
      "use regex test output patterns instead of sed"),
     (uprefix + r'(true|exit 0)', "explicit zero exit unnecessary"),
     (uprefix + r'.*(?<!\[)\$\?', "explicit exit code checks unnecessary"),
     (uprefix + r'.*\|\| echo.*(fail|error)',
      "explicit exit code checks unnecessary"),
     (uprefix + r'set -e', "don't use set -e"),
     (uprefix + r'\s', "don't indent commands, use > for continued lines"),
     (r'^  saved backup bundle to \$TESTTMP.*\.hg$', winglobmsg),
     (r'^  changeset .* references (corrupted|missing) \$TESTTMP/.*[^)]$',
      winglobmsg),
     (r'^  pulling from \$TESTTMP/.*[^)]$', winglobmsg, '\$TESTTMP/unix-repo$'),
     (r'^  reverting .*/.*[^)]$', winglobmsg, '\$TESTTMP/unix-repo$'),
     (r'^  cloning subrepo \S+/.*[^)]$', winglobmsg, '\$TESTTMP/unix-repo$'),
     (r'^  pushing to \$TESTTMP/.*[^)]$', winglobmsg, '\$TESTTMP/unix-repo$'),
     (r'^  pushing subrepo \S+/\S+ to.*[^)]$', winglobmsg,
      '\$TESTTMP/unix-repo$'),
     (r'^  moving \S+/.*[^)]$', winglobmsg),
     (r'^  no changes made to subrepo since.*/.*[^)]$',
      winglobmsg, '\$TESTTMP/unix-repo$'),
     (r'^  .*: largefile \S+ not available from file:.*/.*[^)]$',
      winglobmsg, '\$TESTTMP/unix-repo$'),
   ],
   # warnings
   [
     (r'^  [^*?/\n]* \(glob\)$',
      "glob match with no glob character (?*/)"),
   ]
 ]
 
 for i in [0, 1]:
     for p, m in testpats[i]:
         if p.startswith(r'^'):
             p = r"^  [$>] (%s)" % p[1:]
         else:
             p = r"^  [$>] .*(%s)" % p
         utestpats[i].append((p, m))
 
 utestfilters = [
     (r"<<(\S+)((.|\n)*?\n  > \1)", rephere),
     (r"( *)(#([^\n]*\S)?)", repcomment),
 ]
 
 pypats = [
   [
     (r'^\s*def\s*\w+\s*\(.*,\s*\(',
      "tuple parameter unpacking not available in Python 3+"),
     (r'lambda\s*\(.*,.*\)',
      "tuple parameter unpacking not available in Python 3+"),
     (r'(?<!def)\s+(cmp)\(', "cmp is not available in Python 3+"),
     (r'\breduce\s*\(.*', "reduce is not available in Python 3+"),
     (r'\.has_key\b', "dict.has_key is not available in Python 3+"),
     (r'\s<>\s', '<> operator is not available in Python 3+, use !='),
     (r'^\s*\t', "don't use tabs"),
     (r'\S;\s*\n', "semicolon"),
     (r'[^_]_\("[^"]+"\s*%', "don't use % inside _()"),
     (r"[^_]_\('[^']+'\s*%", "don't use % inside _()"),
     (r'(\w|\)),\w', "missing whitespace after ,"),
     (r'(\w|\))[+/*\-<>]\w', "missing whitespace in expression"),
     (r'^\s+(\w|\.)+=\w[^,()\n]*$', "missing whitespace in assignment"),
     (r'(\s+)try:\n((?:\n|\1\s.*\n)+?)\1except.*?:\n'
      r'((?:\n|\1\s.*\n)+?)\1finally:', 'no try/except/finally in Python 2.4'),
     (r'(?<!def)(\s+|^|\()next\(.+\)',
      'no next(foo) in Python 2.4 and 2.5, use foo.next() instead'),
     (r'(\s+)try:\n((?:\n|\1\s.*\n)*?)\1\s*yield\b.*?'
      r'((?:\n|\1\s.*\n)+?)\1finally:',
      'no yield inside try/finally in Python 2.4'),
     (r'.{81}', "line too long"),
     (r' x+[xo][\'"]\n\s+[\'"]x', 'string join across lines with no space'),
     (r'[^\n]\Z', "no trailing newline"),
     (r'(\S[ \t]+|^[ \t]+)\n', "trailing whitespace"),
 #    (r'^\s+[^_ \n][^_. \n]+_[^_\n]+\s*=',
 #     "don't use underbars in identifiers"),
     (r'^\s+(self\.)?[A-za-z][a-z0-9]+[A-Z]\w* = ',
      "don't use camelcase in identifiers"),
     (r'^\s*(if|while|def|class|except|try)\s[^[\n]*:\s*[^\\n]#\s]+',
      "linebreak after :"),
     (r'class\s[^( \n]+:', "old-style class, use class foo(object)"),
     (r'class\s[^( \n]+\(\):',
      "class foo() not available in Python 2.4, use class foo(object)"),
     (r'\b(%s)\(' % '|'.join(keyword.kwlist),
      "Python keyword is not a function"),
     (r',]', "unneeded trailing ',' in list"),
 #    (r'class\s[A-Z][^\(]*\((?!Exception)',
 #     "don't capitalize non-exception classes"),
 #    (r'in range\(', "use xrange"),
 #    (r'^\s*print\s+', "avoid using print in core and extensions"),
     (r'[\x80-\xff]', "non-ASCII character literal"),
     (r'("\')\.format\(', "str.format() not available in Python 2.4"),
     (r'^\s*with\s+', "with not available in Python 2.4"),
     (r'\.isdisjoint\(', "set.isdisjoint not available in Python 2.4"),
     (r'^\s*except.* as .*:', "except as not available in Python 2.4"),
     (r'^\s*os\.path\.relpath', "relpath not available in Python 2.4"),
     (r'(?<!def)\s+(any|all|format)\(',
      "any/all/format not available in Python 2.4"),
     (r'(?<!def)\s+(callable)\(',
      "callable not available in Python 3, use getattr(f, '__call__', None)"),
     (r'if\s.*\selse', "if ... else form not available in Python 2.4"),
     (r'^\s*(%s)\s\s' % '|'.join(keyword.kwlist),
      "gratuitous whitespace after Python keyword"),
     (r'([\(\[][ \t]\S)|(\S[ \t][\)\]])', "gratuitous whitespace in () or []"),
 #    (r'\s\s=', "gratuitous whitespace before ="),
     (r'[^>< ](\+=|-=|!=|<>|<=|>=|<<=|>>=|%=)\S',
      "missing whitespace around operator"),
     (r'[^>< ](\+=|-=|!=|<>|<=|>=|<<=|>>=|%=)\s',
      "missing whitespace around operator"),
     (r'\s(\+=|-=|!=|<>|<=|>=|<<=|>>=|%=)\S',
      "missing whitespace around operator"),
     (r'[^^+=*/!<>&| %-](\s=|=\s)[^= ]',
      "wrong whitespace around ="),
     (r'raise Exception', "don't raise generic exceptions"),
     (r'raise [^,(]+, (\([^\)]+\)|[^,\(\)]+)$',
      "don't use old-style two-argument raise, use Exception(message)"),
     (r' is\s+(not\s+)?["\'0-9-]', "object comparison with literal"),
     (r' [=!]=\s+(True|False|None)',
      "comparison with singleton, use 'is' or 'is not' instead"),
     (r'^\s*(while|if) [01]:',
      "use True/False for constant Boolean expression"),
     (r'(?:(?<!def)\s+|\()hasattr',
      'hasattr(foo, bar) is broken, use util.safehasattr(foo, bar) instead'),
     (r'opener\([^)]*\).read\(',
      "use opener.read() instead"),
     (r'BaseException', 'not in Python 2.4, use Exception'),
     (r'os\.path\.relpath', 'os.path.relpath is not in Python 2.5'),
     (r'opener\([^)]*\).write\(',
      "use opener.write() instead"),
     (r'[\s\(](open|file)\([^)]*\)\.read\(',
      "use util.readfile() instead"),
     (r'[\s\(](open|file)\([^)]*\)\.write\(',
      "use util.readfile() instead"),
     (r'^[\s\(]*(open(er)?|file)\([^)]*\)',
      "always assign an opened file to a variable, and close it afterwards"),
     (r'[\s\(](open|file)\([^)]*\)\.',
      "always assign an opened file to a variable, and close it afterwards"),
     (r'(?i)descendent', "the proper spelling is descendAnt"),
     (r'\.debug\(\_', "don't mark debug messages for translation"),
     (r'\.strip\(\)\.split\(\)', "no need to strip before splitting"),
     (r'^\s*except\s*:', "naked except clause", r'#.*re-raises'),
     (r':\n(    )*( ){1,3}[^ ]', "must indent 4 spaces"),
     (r'ui\.(status|progress|write|note|warn)\([\'\"]x',
      "missing _() in ui message (use () to hide false-positives)"),
     (r'release\(.*wlock, .*lock\)', "wrong lock release order"),
   ],
   # warnings
   [
   ]
 ]
 
 pyfilters = [
     (r"""(?msx)(?P<comment>\#.*?$)|
          ((?P<quote>('''|\"\"\"|(?<!')'(?!')|(?<!")"(?!")))
           (?P<text>(([^\\]|\\.)*?))
           (?P=quote))""", reppython),
 ]
 
 txtfilters = []
 
 txtpats = [
   [
     ('\s$', 'trailing whitespace'),
   ],
   []
 ]
 
 cpats = [
   [
     (r'//', "don't use //-style comments"),
     (r'^  ', "don't use spaces to indent"),
     (r'\S\t', "don't use tabs except for indent"),
     (r'(\S[ \t]+|^[ \t]+)\n', "trailing whitespace"),
     (r'.{81}', "line too long"),
     (r'(while|if|do|for)\(', "use space after while/if/do/for"),
     (r'return\(', "return is not a function"),
     (r' ;', "no space before ;"),
     (r'\w+\* \w+', "use int *foo, not int* foo"),
     (r'\([^\)]+\) \w+', "use (int)foo, not (int) foo"),
     (r'\w+ (\+\+|--)', "use foo++, not foo ++"),
     (r'\w,\w', "missing whitespace after ,"),
     (r'^[^#]\w[+/*]\w', "missing whitespace in expression"),
     (r'^#\s+\w', "use #foo, not # foo"),
     (r'[^\n]\Z', "no trailing newline"),
     (r'^\s*#import\b', "use only #include in standard C code"),
   ],
   # warnings
   []
 ]
 
 cfilters = [
     (r'(/\*)(((\*(?!/))|[^*])*)\*/', repccomment),
     (r'''(?P<quote>(?<!")")(?P<text>([^"]|\\")+)"(?!")''', repquote),
     (r'''(#\s*include\s+<)([^>]+)>''', repinclude),
     (r'(\()([^)]+\))', repcallspaces),
 ]
 
 inutilpats = [
   [
     (r'\bui\.', "don't use ui in util"),
   ],
   # warnings
   []
 ]
 
 inrevlogpats = [
   [
     (r'\brepo\.', "don't use repo in revlog"),
   ],
   # warnings
   []
 ]
 
 checks = [
     ('python', r'.*\.(py|cgi)$', pyfilters, pypats),
     ('test script', r'(.*/)?test-[^.~]*$', testfilters, testpats),
     ('c', r'.*\.c$', cfilters, cpats),
     ('unified test', r'.*\.t$', utestfilters, utestpats),
     ('layering violation repo in revlog', r'mercurial/revlog\.py', pyfilters,
      inrevlogpats),
     ('layering violation ui in util', r'mercurial/util\.py', pyfilters,
      inutilpats),
     ('txt', r'.*\.txt$', txtfilters, txtpats),
 ]
 
 def _preparepats():
     for c in checks:
         failandwarn = c[-1]
         for pats in failandwarn:
             for i, pseq in enumerate(pats):
                 # fix-up regexes for multi-line searches
                 p = pseq[0]
                 # \s doesn't match \n
                 p = re.sub(r'(?<!\\)\\s', r'[ \\t]', p)
                 # [^...] doesn't match newline
                 p = re.sub(r'(?<!\\)\[\^', r'[^\\n', p)
 
                 pats[i] = (re.compile(p, re.MULTILINE),) + pseq[1:]
         filters = c[2]
         for i, flt in enumerate(filters):
             filters[i] = re.compile(flt[0]), flt[1]
 _preparepats()
 
 class norepeatlogger(object):
     def __init__(self):
         self._lastseen = None
 
     def log(self, fname, lineno, line, msg, blame):
         """print error related a to given line of a given file.
 
         The faulty line will also be printed but only once in the case
         of multiple errors.
 
         :fname: filename
         :lineno: line number
         :line: actual content of the line
         :msg: error message
         """
         msgid = fname, lineno, line
         if msgid != self._lastseen:
             if blame:
                 print "%s:%d (%s):" % (fname, lineno, blame)
             else:
                 print "%s:%d:" % (fname, lineno)
             print " > %s" % line
             self._lastseen = msgid
         print " " + msg
 
 _defaultlogger = norepeatlogger()
 
 def getblame(f):
     lines = []
     for l in os.popen('hg annotate -un %s' % f):
         start, line = l.split(':', 1)
         user, rev = start.split()
         lines.append((line[1:-1], user, rev))
     return lines
 
 def checkfile(f, logfunc=_defaultlogger.log, maxerr=None, warnings=False,
               blame=False, debug=False, lineno=True):
     """checks style and portability of a given file
 
     :f: filepath
     :logfunc: function used to report error
               logfunc(filename, linenumber, linecontent, errormessage)
     :maxerr: number of error to display before aborting.
              Set to false (default) to report all errors
 
     return True if no error is found, False otherwise.
     """
     blamecache = None
     result = True
     for name, match, filters, pats in checks:
         if debug:
             print name, f
         fc = 0
         if not re.match(match, f):
             if debug:
                 print "Skipping %s for %s it doesn't match %s" % (
                        name, match, f)
             continue
         try:
             fp = open(f)
         except IOError, e:
             print "Skipping %s, %s" % (f, str(e).split(':', 1)[0])
             continue
         pre = post = fp.read()
         fp.close()
         if "no-" "check-code" in pre:
             if debug:
                 print "Skipping %s for %s it has no-" " check-code" % (
                        name, f)
             break
         for p, r in filters:
             post = re.sub(p, r, post)
         nerrs = len(pats[0]) # nerr elements are errors
         if warnings:
             pats = pats[0] + pats[1]
         else:
             pats = pats[0]
         # print post # uncomment to show filtered version
 
         if debug:
             print "Checking %s for %s" % (name, f)
 
         prelines = None
         errors = []
         for i, pat in enumerate(pats):
             if len(pat) == 3:
                 p, msg, ignore = pat
             else:
                 p, msg = pat
                 ignore = None
 
             pos = 0
             n = 0
             for m in p.finditer(post):
                 if prelines is None:
                     prelines = pre.splitlines()
                     postlines = post.splitlines(True)
 
                 start = m.start()
                 while n < len(postlines):
                     step = len(postlines[n])
                     if pos + step > start:
                         break
                     pos += step
                     n += 1
                 l = prelines[n]
 
                 if "check-code" "-ignore" in l:
                     if debug:
                         print "Skipping %s for %s:%s (check-code" "-ignore)" % (
                             name, f, n)
                     continue
                 elif ignore and re.search(ignore, l, re.MULTILINE):
                     continue
                 bd = ""
                 if blame:
                     bd = 'working directory'
                     if not blamecache:
                         blamecache = getblame(f)
                     if n < len(blamecache):
                         bl, bu, br = blamecache[n]
                         if bl == l:
                             bd = '%s@%s' % (bu, br)
                 if i >= nerrs:
                     msg = "warning: " + msg
                 errors.append((f, lineno and n + 1, l, msg, bd))
                 result = False
 
         errors.sort()
         for e in errors:
             logfunc(*e)
             fc += 1
             if maxerr and fc >= maxerr:
                 print " (too many errors, giving up)"
                 break
 
     return result
 
 if __name__ == "__main__":
     parser = optparse.OptionParser("%prog [options] [files]")
     parser.add_option("-w", "--warnings", action="store_true",
                       help="include warning-level checks")
     parser.add_option("-p", "--per-file", type="int",
                       help="max warnings per file")
     parser.add_option("-b", "--blame", action="store_true",
                       help="use annotate to generate blame info")
     parser.add_option("", "--debug", action="store_true",
                       help="show debug information")
     parser.add_option("", "--nolineno", action="store_false",
                       dest='lineno', help="don't show line numbers")
 
     parser.set_defaults(per_file=15, warnings=False, blame=False, debug=False,
                         lineno=True)
     (options, args) = parser.parse_args()
 
     if len(args) == 0:
         check = glob.glob("*")
     else:
         check = args
 
     ret = 0
     for f in check:
         if not checkfile(f, maxerr=options.per_file, warnings=options.warnings,
                          blame=options.blame, debug=options.debug,
                          lineno=options.lineno):
             ret = 1
     sys.exit(ret)

tests/test-import-merge.t

@@ -1,153 +1,155 b''
   $ echo "[extensions]" >> $HGRCPATH
   $ echo "mq=" >> $HGRCPATH
 
   $ tipparents() {
   > hg parents --template "{rev}:{node|short} {desc|firstline}\n" -r tip
   > }
 
 Test import and merge diffs
 
   $ hg init repo
   $ cd repo
   $ echo a > a
   $ hg ci -Am adda
   adding a
   $ echo a >> a
   $ hg ci -m changea
   $ echo c > c
   $ hg ci -Am addc
   adding c
   $ hg up 0
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ echo b > b
   $ hg ci -Am addb
   adding b
   created new head
   $ hg up 1
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 3
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m merge
   $ hg export . > ../merge.diff
   $ cd ..
   $ hg clone -r2 repo repo2
   adding changesets
   adding manifests
   adding file changes
   added 3 changesets with 3 changes to 2 files
   updating to branch default
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cd repo2
   $ hg pull -r3 ../repo
   pulling from ../repo
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 1 changesets with 1 changes to 1 files (+1 heads)
   (run 'hg heads' to see heads, 'hg merge' to merge)
 
 Test without --exact and diff.p1 == workingdir.p1
 
   $ hg up 1
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg import ../merge.diff
   applying ../merge.diff
   $ tipparents
   1:540395c44225 changea
   3:102a90ea7b4a addb
   $ hg strip --no-backup tip
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
 
 Test without --exact and diff.p1 != workingdir.p1
 
   $ hg up 2
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg import ../merge.diff
   applying ../merge.diff
   $ tipparents
   2:890ecaa90481 addc
   $ hg strip --no-backup tip
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
 
 Test with --exact
 
   $ hg import --exact ../merge.diff
   applying ../merge.diff
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ tipparents
   1:540395c44225 changea
   3:102a90ea7b4a addb
   $ hg strip --no-backup tip
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
 
 Test with --bypass and diff.p1 == workingdir.p1
 
   $ hg up 1
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg import --bypass ../merge.diff
   applying ../merge.diff
   $ tipparents
   1:540395c44225 changea
   3:102a90ea7b4a addb
   $ hg strip --no-backup tip
 
 Test with --bypass and diff.p1 != workingdir.p1
 
   $ hg up 2
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg import --bypass ../merge.diff
   applying ../merge.diff
   $ tipparents
   2:890ecaa90481 addc
   $ hg strip --no-backup tip
 
 Test with --bypass and --exact
 
   $ hg import --bypass --exact ../merge.diff
   applying ../merge.diff
   $ tipparents
   1:540395c44225 changea
   3:102a90ea7b4a addb
   $ hg strip --no-backup tip
 
   $ cd ..
 
 Test that --exact on a bad header doesn't corrupt the repo (issue3616)
 
   $ hg init repo3
   $ cd repo3
   $ echo a>a
   $ hg ci -Aqm0
   $ echo a>>a
   $ hg ci -m1
   $ echo a>>a
   $ hg ci -m2
   $ echo a>a
   $ echo b>>a
   $ echo a>>a
   $ hg ci -m3
   $ hg export 2 | head -7 > ../a.patch
-  $ hg export tip | tail -n +8 >> ../a.patch
+  $ hg export tip > out
+  >>> apatch = open("../a.patch", "a")
+  >>> apatch.write("".join(open("out").readlines()[7:]))
 
   $ cd ..
   $ hg clone -qr0 repo3 repo3-clone
   $ cd repo3-clone
   $ hg pull -qr1 ../repo3
 
   $ hg import --exact ../a.patch
   applying ../a.patch
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   patching file a
   Hunk #1 succeeded at 1 with fuzz 1 (offset -1 lines).
   transaction abort!
   rollback completed
   abort: patch is damaged or loses information
   [255]
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   1 files, 2 changesets, 2 total revisions