[PATCH 1 of 2 STABLE] hook: raise a more special HookAbort exception when a hook fails

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at fb.com>
# Date 1417317215 28800
#      Sat Nov 29 19:13:35 2014 -0800
# Branch stable
# Node ID 24883146c0e464584151b960c220572c80541529
# Parent  edf29f9c15f0f171847f4c7a8184cca4e95c8b31
hook: raise a more special HookAbort exception when a hook fails

We need to gracefully handle some abort for pushkey, especially because it lead
to user-facing crash over the wireprotocols. So we needs a more specialised
exception to catch.

diff --git a/mercurial/error.py b/mercurial/error.py
--- a/mercurial/error.py
+++ b/mercurial/error.py
@@ -46,10 +46,16 @@ class Abort(Exception):
     """Raised if a command needs to print an error and exit."""
     def __init__(self, *args, **kw):
         Exception.__init__(self, *args)
         self.hint = kw.get('hint')
 
+class HookAbort(Abort):
+    """raised when a validation hook fails aborting an operation
+
+    Exists to allow more specialized catching."""
+    pass
+
 class ConfigError(Abort):
     """Exception raised when parsing config files"""
 
 class OutOfBandError(Exception):
     """Exception raised when a remote repo reports failure"""
diff --git a/mercurial/hook.py b/mercurial/hook.py
--- a/mercurial/hook.py
+++ b/mercurial/hook.py
@@ -5,11 +5,11 @@
 # 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, time
-import extensions, util, demandimport
+import extensions, util, demandimport, error
 
 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
@@ -105,11 +105,11 @@ def _pythonhook(ui, repo, name, hname, f
         duration = time.time() - starttime
         ui.log('pythonhook', 'pythonhook-%s: %s finished in %0.2f seconds\n',
                name, funcname, duration)
     if r:
         if throw:
-            raise util.Abort(_('%s hook failed') % hname)
+            raise error.HookAbort(_('%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))
@@ -140,11 +140,11 @@ def _exthook(ui, repo, name, cmd, args, 
     ui.log('exthook', 'exthook-%s: %s finished in %0.2f seconds\n',
            name, cmd, duration)
     if r:
         desc, r = util.explainexit(r)
         if throw:
-            raise util.Abort(_('%s hook %s') % (name, desc))
+            raise error.HookAbort(_('%s hook %s') % (name, desc))
         ui.warn(_('warning: %s hook %s\n') % (name, desc))
     return r
 
 def _allhooks(ui):
     hooks = []