[PATCH 2 of 6 mergedriver] hook: factor out determination of hooks from running them

[Siddharth Agarwal]

# HG changeset patch
# User Siddharth Agarwal <sid0 at fb.com>
# Date 1444864411 25200
#      Wed Oct 14 16:13:31 2015 -0700
# Node ID cac30541d1702220d3737fc85382ca136cec06d9
# Parent  2a42915e11423eaa1e127e12333a890655c8bb76
hook: factor out determination of hooks from running them

This will allow other code to run a predetermined series of hooks.

diff --git a/mercurial/hook.py b/mercurial/hook.py
--- a/mercurial/hook.py
+++ b/mercurial/hook.py
@@ -162,14 +162,19 @@ def hook(ui, repo, name, throw=False, **
     if not ui.callhooks:
         return False
 
+    hooks = []
+    for hname, cmd in _allhooks(ui):
+        if hname.split('.')[0] == name and cmd:
+            hooks.append((hname, cmd))
+
+    return runhooks(ui, repo, name, hooks, throw=throw, **args)
+
+def runhooks(ui, repo, name, hooks, throw=False, **args):
     r = False
     oldstdout = -1
 
     try:
-        for hname, cmd in _allhooks(ui):
-            if hname.split('.')[0] != name or not cmd:
-                continue
-
+        for hname, cmd in hooks:
             if oldstdout == -1 and _redirect:
                 try:
                     stdoutno = sys.__stdout__.fileno()