# HG changeset patch
# User Matt Mackall <mpm@selenic.com>
# Date 2012-05-12 10:23:49
# Node ID ea7bf1d49bce6bb28c26a36c4c1538a857e744aa
# Parent  de4b42daf396b000e73c0cc0217a5fde0a88ac8f
# Parent  2fdd1902ed2d0862afd51f956379b0effac4e884

merge with stable

diff --git a/hgext/bugzilla.py b/hgext/bugzilla.py
--- a/hgext/bugzilla.py
+++ b/hgext/bugzilla.py
@@ -585,11 +585,13 @@ class cookietransportrequest(object):
 # inheritance with a new-style class.
 class cookietransport(cookietransportrequest, xmlrpclib.Transport):
     def __init__(self, use_datetime=0):
-        xmlrpclib.Transport.__init__(self, use_datetime)
+        if util.safehasattr(xmlrpclib.Transport, "__init__"):
+            xmlrpclib.Transport.__init__(self, use_datetime)
 
 class cookiesafetransport(cookietransportrequest, xmlrpclib.SafeTransport):
     def __init__(self, use_datetime=0):
-        xmlrpclib.SafeTransport.__init__(self, use_datetime)
+        if util.safehasattr(xmlrpclib.Transport, "__init__"):
+            xmlrpclib.SafeTransport.__init__(self, use_datetime)
 
 class bzxmlrpc(bzaccess):
     """Support for access to Bugzilla via the Bugzilla XMLRPC API.
diff --git a/hgext/pager.py b/hgext/pager.py
--- a/hgext/pager.py
+++ b/hgext/pager.py
@@ -85,10 +85,8 @@ def uisetup(ui):
                  (cmd not in ui.configlist('pager', 'ignore') and not attend))):
                 ui.setconfig('ui', 'formatted', ui.formatted())
                 ui.setconfig('ui', 'interactive', False)
-                try:
+                if util.safehasattr(signal, "SIGPIPE"):
                     signal.signal(signal.SIGPIPE, signal.SIG_DFL)
-                except ValueError:
-                    pass
                 _runpager(p)
         return orig(ui, options, cmd, cmdfunc)
 
diff --git a/mercurial/diffhelpers.c b/mercurial/diffhelpers.c
--- a/mercurial/diffhelpers.c
+++ b/mercurial/diffhelpers.c
@@ -135,7 +135,7 @@ testhunk(PyObject *self, PyObject *args)
 		return NULL;
 	alen = PyList_Size(a);
 	blen = PyList_Size(b);
-	if (alen > blen - bstart) {
+	if (alen > blen - bstart || bstart < 0) {
 		return Py_BuildValue("l", -1);
 	}
 	for (i = 0; i < alen; i++) {
diff --git a/mercurial/patch.py b/mercurial/patch.py
--- a/mercurial/patch.py
+++ b/mercurial/patch.py
@@ -1014,9 +1014,9 @@ class hunk(object):
         oldstart = self.starta + top
         newstart = self.startb + top
         # zero length hunk ranges already have their start decremented
-        if self.lena:
+        if self.lena and oldstart > 0:
             oldstart -= 1
-        if self.lenb:
+        if self.lenb and newstart > 0:
             newstart -= 1
         return old, oldstart, new, newstart
 
diff --git a/tests/test-import.t b/tests/test-import.t
--- a/tests/test-import.t
+++ b/tests/test-import.t
@@ -997,6 +997,26 @@ import a unified diff with no lines of c
   c3
   c4
 
+no segfault while importing a unified diff which start line is zero but chunk
+size is non-zero
+
+  $ hg init startlinezero
+  $ cd startlinezero
+  $ echo foo > foo
+  $ hg commit -Amfoo
+  adding foo
+
+  $ hg import --no-commit - << EOF
+  > diff a/foo b/foo
+  > --- a/foo
+  > +++ b/foo
+  > @@ -0,1 +0,1 @@
+  >  foo
+  > EOF
+  applying patch from stdin
+
+  $ cd ..
+
 Test corner case involving fuzz and skew
 
   $ hg init morecornercases