[PATCH evolve-ext] evolve: prevent a crash in httpclient_pushobsmarkers() when pushing

[Matt Harbison]

# HG changeset patch
# User Matt Harbison <matt_harbison at yahoo.com>
# Date 1425603727 18000
#      Thu Mar 05 20:02:07 2015 -0500
# Branch stable
# Node ID 0828a7e7f402374dca9cc089a9ff958fb478163c
# Parent  1e7c8046a9f461bda3c8f6003dae65e235af8bb6
evolve: prevent a crash in httpclient_pushobsmarkers() when pushing

I've been running into a crash when pushing from my hg repo in a Fedora 16 VM to
Win7 running 'hg serve', even with extensions disabled on both sides:

  ../hg push -r . pc
  pushing to http://192.168.1.4:8000/
  searching for changes
  no changes found
  pushing 2 obsolescence markers (263 bytes)
  ** unknown exception encountered, please report by visiting
  ...
  File "hg-evolve/hgext/evolve.py", line 2482, in _pushobsolete
    remote.evoext_pushobsmarkers_0(obsdata)
  File "hg-evolve/hgext/evolve.py", line 2522, in httpclient_pushobsmarkers
    ret, output = self._call('evoext_pushobsmarkers_0', data=obsfile)
  ValueError: too many values to unpack

I'm not sure how this repo differs from the one in the test suite, so I'm not
sure how to craft a test for this.  The failure occurs even when there _are_
csets to push.  There was no crash if no obsolete markers needed to be pushed.

At any rate, this code was stolen from httppeer._callpush(), where it calls
self._call().  The socket exception handling wasn't necessary to fix the crash,
but the calling code might as well be duplicated in its entirety.

A successful push with this patch looks like this.  Note the final line is _not_
in the output of the http push in test-simple4server.t:

  ../hg push -r . pc
  pushing to http://192.168.1.4:8000/
  searching for changes
  remote has heads on branch 'default' that are not known locally: 3af110194a0c
      56000e3ae44d 57ac6e51d290 7da4355c21b8 and 8 others
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 0 changes to 1 files (+1 heads)
  pushing 4 obsolescence markers (525 bytes)
  remote: 2 obsolescence markers added

diff --git a/hgext/evolve.py b/hgext/evolve.py
--- a/hgext/evolve.py
+++ b/hgext/evolve.py
@@ -2519,11 +2519,20 @@
     (Cannot simply use _callpush as http is doing some special handling)"""
     self.requirecap('_evoext_pushobsmarkers_0',
                     _('push obsolete markers faster'))
-    ret, output = self._call('evoext_pushobsmarkers_0', data=obsfile)
-    for l in output.splitlines(True):
-        if l.strip():
-            self.ui.status(_('remote: '), l)
-    return ret
+    try:
+        r = self._call('evoext_pushobsmarkers_0', data=obsfile)
+        vals = r.split('\n', 1)
+        if len(vals) < 2:
+            raise error.ResponseError(_("unexpected response:"), r)
+
+        for l in vals[1].splitlines(True):
+            if l.strip():
+                self.ui.status(_('remote: '), l)
+        return vals[0]
+    except socket.error, err:
+        if err.args[0] in (errno.ECONNRESET, errno.EPIPE):
+            raise util.Abort(_('push failed: %s') % err.args[1])
+        raise util.Abort(err.args[1])
 
 @eh.wrapfunction(localrepo.localrepository, '_restrictcapabilities')
 def local_pushobsmarker_capabilities(orig, repo, caps):