hghave: use a less brittle have-json check

tests/hghave.py

@@ -1,364 +1,367
 import os, stat
 import re
 import socket
 import sys
 import tempfile
 
 tempprefix = 'hg-hghave-'
 
 checks = {
     "true": (lambda: True, "yak shaving"),
     "false": (lambda: False, "nail clipper"),
 }
 
 def check(name, desc):
     def decorator(func):
         checks[name] = (func, desc)
         return func
     return decorator
 
 def matchoutput(cmd, regexp, ignorestatus=False):
     """Return True if cmd executes successfully and its output
     is matched by the supplied regular expression.
     """
     r = re.compile(regexp)
     fh = os.popen(cmd)
     s = fh.read()
     try:
         ret = fh.close()
     except IOError:
         # Happen in Windows test environment
         ret = 1
     return (ignorestatus or ret is None) and r.search(s)
 
 @check("baz", "GNU Arch baz client")
 def has_baz():
     return matchoutput('baz --version 2>&1', r'baz Bazaar version')
 
 @check("bzr", "Canonical's Bazaar client")
 def has_bzr():
     try:
         import bzrlib
         return bzrlib.__doc__ is not None
     except ImportError:
         return False
 
 @check("bzr114", "Canonical's Bazaar client >= 1.14")
 def has_bzr114():
     try:
         import bzrlib
         return (bzrlib.__doc__ is not None
                 and bzrlib.version_info[:2] >= (1, 14))
     except ImportError:
         return False
 
 @check("cvs", "cvs client/server")
 def has_cvs():
     re = r'Concurrent Versions System.*?server'
     return matchoutput('cvs --version 2>&1', re) and not has_msys()
 
 @check("cvs112", "cvs client/server >= 1.12")
 def has_cvs112():
     re = r'Concurrent Versions System \(CVS\) 1.12.*?server'
     return matchoutput('cvs --version 2>&1', re) and not has_msys()
 
 @check("darcs", "darcs client")
 def has_darcs():
     return matchoutput('darcs --version', r'2\.[2-9]', True)
 
 @check("mtn", "monotone client (>= 1.0)")
 def has_mtn():
     return matchoutput('mtn --version', r'monotone', True) and not matchoutput(
         'mtn --version', r'monotone 0\.', True)
 
 @check("eol-in-paths", "end-of-lines in paths")
 def has_eol_in_paths():
     try:
         fd, path = tempfile.mkstemp(dir='.', prefix=tempprefix, suffix='\n\r')
         os.close(fd)
         os.remove(path)
         return True
     except (IOError, OSError):
         return False
 
 @check("execbit", "executable bit")
 def has_executablebit():
     try:
         EXECFLAGS = stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH
         fh, fn = tempfile.mkstemp(dir='.', prefix=tempprefix)
         try:
             os.close(fh)
             m = os.stat(fn).st_mode & 0777
             new_file_has_exec = m & EXECFLAGS
             os.chmod(fn, m ^ EXECFLAGS)
             exec_flags_cannot_flip = ((os.stat(fn).st_mode & 0777) == m)
         finally:
             os.unlink(fn)
     except (IOError, OSError):
         # we don't care, the user probably won't be able to commit anyway
         return False
     return not (new_file_has_exec or exec_flags_cannot_flip)
 
 @check("icasefs", "case insensitive file system")
 def has_icasefs():
     # Stolen from mercurial.util
     fd, path = tempfile.mkstemp(dir='.', prefix=tempprefix)
     os.close(fd)
     try:
         s1 = os.stat(path)
         d, b = os.path.split(path)
         p2 = os.path.join(d, b.upper())
         if path == p2:
             p2 = os.path.join(d, b.lower())
         try:
             s2 = os.stat(p2)
             return s2 == s1
         except OSError:
             return False
     finally:
         os.remove(path)
 
 @check("fifo", "named pipes")
 def has_fifo():
     if getattr(os, "mkfifo", None) is None:
         return False
     name = tempfile.mktemp(dir='.', prefix=tempprefix)
     try:
         os.mkfifo(name)
         os.unlink(name)
         return True
     except OSError:
         return False
 
 @check("killdaemons", 'killdaemons.py support')
 def has_killdaemons():
     return True
 
 @check("cacheable", "cacheable filesystem")
 def has_cacheable_fs():
     from mercurial import util
 
     fd, path = tempfile.mkstemp(dir='.', prefix=tempprefix)
     os.close(fd)
     try:
         return util.cachestat(path).cacheable()
     finally:
         os.remove(path)
 
 @check("lsprof", "python lsprof module")
 def has_lsprof():
     try:
         import _lsprof
         _lsprof.Profiler # silence unused import warning
         return True
     except ImportError:
         return False
 
 @check("gettext", "GNU Gettext (msgfmt)")
 def has_gettext():
     return matchoutput('msgfmt --version', 'GNU gettext-tools')
 
 @check("git", "git command line client")
 def has_git():
     return matchoutput('git --version 2>&1', r'^git version')
 
 @check("docutils", "Docutils text processing library")
 def has_docutils():
     try:
         from docutils.core import publish_cmdline
         publish_cmdline # silence unused import
         return True
     except ImportError:
         return False
 
 def getsvnversion():
     m = matchoutput('svn --version --quiet 2>&1', r'^(\d+)\.(\d+)')
     if not m:
         return (0, 0)
     return (int(m.group(1)), int(m.group(2)))
 
 @check("svn15", "subversion client and admin tools >= 1.5")
 def has_svn15():
     return getsvnversion() >= (1, 5)
 
 @check("svn13", "subversion client and admin tools >= 1.3")
 def has_svn13():
     return getsvnversion() >= (1, 3)
 
 @check("svn", "subversion client and admin tools")
 def has_svn():
     return matchoutput('svn --version 2>&1', r'^svn, version') and \
         matchoutput('svnadmin --version 2>&1', r'^svnadmin, version')
 
 @check("svn-bindings", "subversion python bindings")
 def has_svn_bindings():
     try:
         import svn.core
         version = svn.core.SVN_VER_MAJOR, svn.core.SVN_VER_MINOR
         if version < (1, 4):
             return False
         return True
     except ImportError:
         return False
 
 @check("p4", "Perforce server and client")
 def has_p4():
     return (matchoutput('p4 -V', r'Rev\. P4/') and
             matchoutput('p4d -V', r'Rev\. P4D/'))
 
 @check("symlink", "symbolic links")
 def has_symlink():
     if getattr(os, "symlink", None) is None:
         return False
     name = tempfile.mktemp(dir='.', prefix=tempprefix)
     try:
         os.symlink(".", name)
         os.unlink(name)
         return True
     except (OSError, AttributeError):
         return False
 
 @check("hardlink", "hardlinks")
 def has_hardlink():
     from mercurial import util
     fh, fn = tempfile.mkstemp(dir='.', prefix=tempprefix)
     os.close(fh)
     name = tempfile.mktemp(dir='.', prefix=tempprefix)
     try:
         try:
             util.oslink(fn, name)
             os.unlink(name)
             return True
         except OSError:
             return False
     finally:
         os.unlink(fn)
 
 @check("tla", "GNU Arch tla client")
 def has_tla():
     return matchoutput('tla --version 2>&1', r'The GNU Arch Revision')
 
 @check("gpg", "gpg client")
 def has_gpg():
     return matchoutput('gpg --version 2>&1', r'GnuPG')
 
 @check("unix-permissions", "unix-style permissions")
 def has_unix_permissions():
     d = tempfile.mkdtemp(dir='.', prefix=tempprefix)
     try:
         fname = os.path.join(d, 'foo')
         for umask in (077, 007, 022):
             os.umask(umask)
             f = open(fname, 'w')
             f.close()
             mode = os.stat(fname).st_mode
             os.unlink(fname)
             if mode & 0777 != ~umask & 0666:
                 return False
         return True
     finally:
         os.rmdir(d)
 
 @check("unix-socket", "AF_UNIX socket family")
 def has_unix_socket():
     return getattr(socket, 'AF_UNIX', None) is not None
 
 @check("root", "root permissions")
 def has_root():
     return getattr(os, 'geteuid', None) and os.geteuid() == 0
 
 @check("pyflakes", "Pyflakes python linter")
 def has_pyflakes():
     return matchoutput("sh -c \"echo 'import re' 2>&1 | pyflakes\"",
                        r"<stdin>:1: 're' imported but unused",
                        True)
 
 @check("pygments", "Pygments source highlighting library")
 def has_pygments():
     try:
         import pygments
         pygments.highlight # silence unused import warning
         return True
     except ImportError:
         return False
 
 @check("python243", "python >= 2.4.3")
 def has_python243():
     return sys.version_info >= (2, 4, 3)
 
 @check("json", "some json module available")
 def has_json():
     try:
-        if sys.version_info < (2, 7):
-            import simplejson as json
-        else:
-            import json
+        import json
         json.dumps
         return True
     except ImportError:
-        return False
+        try:
+            import simplejson as json
+            json.dumps
+            return True
+        except ImportError:
+            pass
+    return False
 
 @check("outer-repo", "outer repo")
 def has_outer_repo():
     # failing for other reasons than 'no repo' imply that there is a repo
     return not matchoutput('hg root 2>&1',
                            r'abort: no repository found', True)
 
 @check("ssl", "python >= 2.6 ssl module and python OpenSSL")
 def has_ssl():
     try:
         import ssl
         ssl.wrap_socket # silence unused import warning
         import OpenSSL
         OpenSSL.SSL.Context
         return True
     except ImportError:
         return False
 
 @check("windows", "Windows")
 def has_windows():
     return os.name == 'nt'
 
 @check("system-sh", "system() uses sh")
 def has_system_sh():
     return os.name != 'nt'
 
 @check("serve", "platform and python can manage 'hg serve -d'")
 def has_serve():
     return os.name != 'nt' # gross approximation
 
 @check("test-repo", "running tests from repository")
 def has_test_repo():
     t = os.environ["TESTDIR"]
     return os.path.isdir(os.path.join(t, "..", ".hg"))
 
 @check("tic", "terminfo compiler and curses module")
 def has_tic():
     try:
         import curses
         curses.COLOR_BLUE
         return matchoutput('test -x "`which tic`"', '')
     except ImportError:
         return False
 
 @check("msys", "Windows with MSYS")
 def has_msys():
     return os.getenv('MSYSTEM')
 
 @check("aix", "AIX")
 def has_aix():
     return sys.platform.startswith("aix")
 
 @check("osx", "OS X")
 def has_osx():
     return sys.platform == 'darwin'
 
 @check("absimport", "absolute_import in __future__")
 def has_absimport():
     import __future__
     from mercurial import util
     return util.safehasattr(__future__, "absolute_import")
 
 @check("py3k", "running with Python 3.x")
 def has_py3k():
     return 3 == sys.version_info[0]