hooks: use python 2.4 compatible exception handling

mercurial/hook.py

@@ -1,167 +1,168 b''
 # hook.py - hook support for mercurial
 #
 # Copyright 2007 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.
 
 from i18n import _
 import os, sys
 import extensions, util
 
 def _pythonhook(ui, repo, name, hname, funcname, args, throw):
     '''call python hook. hook is callable object, looked up as
     name in python module. if callable returns "true", hook
     fails, else passes. if hook raises exception, treated as
     hook failure. exception propagates if throw is "true".
 
     reason for "true" meaning "hook failed" is so that
     unmodified commands (e.g. mercurial.commands.update) can
     be run as hooks without wrappers to convert return values.'''
 
     ui.note(_("calling hook %s: %s\n") % (hname, funcname))
     obj = funcname
     if not hasattr(obj, '__call__'):
         d = funcname.rfind('.')
         if d == -1:
             raise util.Abort(_('%s hook is invalid ("%s" not in '
                                'a module)') % (hname, funcname))
         modname = funcname[:d]
         oldpaths = sys.path
         if hasattr(sys, "frozen"):
             # binary installs require sys.path manipulation
             modpath, modfile = os.path.split(modname)
             if modpath and modfile:
                 sys.path = sys.path[:] + [modpath]
                 modname = modfile
         try:
             obj = __import__(modname)
         except ImportError:
             e1 = sys.exc_type, sys.exc_value, sys.exc_traceback
             try:
                 # extensions are loaded with hgext_ prefix
                 obj = __import__("hgext_%s" % modname)
             except ImportError:
                 e2 = sys.exc_type, sys.exc_value, sys.exc_traceback
                 if ui.tracebackflag:
                     ui.warn(_('exception from first failed import attempt:\n'))
                 ui.traceback(e1)
                 if ui.tracebackflag:
                     ui.warn(_('exception from second failed import attempt:\n'))
                 ui.traceback(e2)
                 raise util.Abort(_('%s hook is invalid '
                                    '(import of "%s" failed)') %
                                  (hname, modname))
         sys.path = oldpaths
         try:
             for p in funcname.split('.')[1:]:
                 obj = getattr(obj, p)
         except AttributeError:
             raise util.Abort(_('%s hook is invalid '
                                '("%s" is not defined)') %
                              (hname, funcname))
         if not hasattr(obj, '__call__'):
             raise util.Abort(_('%s hook is invalid '
                                '("%s" is not callable)') %
                              (hname, funcname))
     try:
-        # redirect IO descriptors the the ui descriptors so hooks that write
-        # directly to these don't mess the command protocol when running through
-        # the command server
+        try:
+            # redirect IO descriptors the the ui descriptors so hooks
+            # that write directly to these don't mess up the command
+            # protocol when running through the command server
         old = sys.stdout, sys.stderr, sys.stdin
         sys.stdout, sys.stderr, sys.stdin = ui.fout, ui.ferr, ui.fin
 
         r = obj(ui=ui, repo=repo, hooktype=name, **args)
     except KeyboardInterrupt:
         raise
     except Exception, exc:
         if isinstance(exc, util.Abort):
             ui.warn(_('error: %s hook failed: %s\n') %
                          (hname, exc.args[0]))
         else:
             ui.warn(_('error: %s hook raised an exception: '
                            '%s\n') % (hname, exc))
         if throw:
             raise
         ui.traceback()
         return True
     finally:
         sys.stdout, sys.stderr, sys.stdin = old
     if r:
         if throw:
             raise util.Abort(_('%s hook failed') % hname)
         ui.warn(_('warning: %s hook failed\n') % hname)
     return r
 
 def _exthook(ui, repo, name, cmd, args, throw):
     ui.note(_("running hook %s: %s\n") % (name, cmd))
 
     env = {}
     for k, v in args.iteritems():
         if hasattr(v, '__call__'):
             v = v()
         if isinstance(v, dict):
             # make the dictionary element order stable across Python
             # implementations
             v = ('{' +
                  ', '.join('%r: %r' % i for i in sorted(v.iteritems())) +
                  '}')
         env['HG_' + k.upper()] = v
 
     if repo:
         cwd = repo.root
     else:
         cwd = os.getcwd()
     if 'HG_URL' in env and env['HG_URL'].startswith('remote:http'):
         r = util.system(cmd, environ=env, cwd=cwd, out=ui)
     else:
         r = util.system(cmd, environ=env, cwd=cwd, out=ui.fout)
     if r:
         desc, r = util.explainexit(r)
         if throw:
             raise util.Abort(_('%s hook %s') % (name, desc))
         ui.warn(_('warning: %s hook %s\n') % (name, desc))
     return r
 
 _redirect = False
 def redirect(state):
     global _redirect
     _redirect = state
 
 def hook(ui, repo, name, throw=False, **args):
     r = False
 
     oldstdout = -1
     if _redirect:
         stdoutno = sys.__stdout__.fileno()
         stderrno = sys.__stderr__.fileno()
         # temporarily redirect stdout to stderr, if possible
         if stdoutno >= 0 and stderrno >= 0:
             oldstdout = os.dup(stdoutno)
             os.dup2(stderrno, stdoutno)
 
     try:
         for hname, cmd in ui.configitems('hooks'):
             if hname.split('.')[0] != name or not cmd:
                 continue
             if hasattr(cmd, '__call__'):
                 r = _pythonhook(ui, repo, name, hname, cmd, args, throw) or r
             elif cmd.startswith('python:'):
                 if cmd.count(':') >= 2:
                     path, cmd = cmd[7:].rsplit(':', 1)
                     path = util.expandpath(path)
                     if repo:
                         path = os.path.join(repo.root, path)
                     mod = extensions.loadpath(path, 'hghook.%s' % hname)
                     hookfn = getattr(mod, cmd)
                 else:
                     hookfn = cmd[7:].strip()
                 r = _pythonhook(ui, repo, name, hname, hookfn, args, throw) or r
             else:
                 r = _exthook(ui, repo, hname, cmd, args, throw) or r
     finally:
         if _redirect and oldstdout >= 0:
             os.dup2(oldstdout, stdoutno)
             os.close(oldstdout)
 
     return r