upload: Catch and cleanly report connectivity errors

Instead of giving a Python backtrace when there is a connectivity
problem during repo upload, report that we cannot access the host,
and why, with a halfway decent error message.

Bug: REPO-45
Change-Id: I9a45b387e86e48073a2d99bd6d594c1a7d6d99d4
Signed-off-by: Shawn O. Pearce <sop@google.com>
(cherry picked from commit d2dfac81ad6a060179b4b2289060af2dc7a5cdfd)
diff --git a/git_config.py b/git_config.py
index 26fc970..19c19f1 100644
--- a/git_config.py
+++ b/git_config.py
@@ -23,6 +23,8 @@
 except ImportError:
   import dummy_threading as _threading
 import time
+import urllib2
+
 from signal import SIGTERM
 from urllib2 import urlopen, HTTPError
 from error import GitError, UploadError
@@ -563,23 +565,25 @@
         try:
           info = urlopen(u).read()
           if info == 'NOT_AVAILABLE':
-            raise UploadError('Upload over ssh unavailable')
+            raise UploadError('%s: SSH disabled' % self.review)
           if '<' in info:
             # Assume the server gave us some sort of HTML
             # response back, like maybe a login page.
             #
-            raise UploadError('Cannot read %s:\n%s' % (u, info))
+            raise UploadError('%s: Cannot parse response' % u)
 
           self._review_protocol = 'ssh'
           self._review_host = info.split(" ")[0]
           self._review_port = info.split(" ")[1]
+        except urllib2.URLError, e:
+          raise UploadError('%s: %s' % (self.review, e.reason[1]))
         except HTTPError, e:
           if e.code == 404:
             self._review_protocol = 'http-post'
             self._review_host = None
             self._review_port = None
           else:
-            raise UploadError('Cannot guess Gerrit version')
+            raise UploadError('Upload over ssh unavailable')
 
         REVIEW_CACHE[u] = (
           self._review_protocol,
diff --git a/subcmds/upload.py b/subcmds/upload.py
index 1964bff..2082209 100644
--- a/subcmds/upload.py
+++ b/subcmds/upload.py
@@ -283,15 +283,19 @@
         have_errors = True
 
     print >>sys.stderr, ''
-    print >>sys.stderr, '--------------------------------------------'
+    print >>sys.stderr, '----------------------------------------------------------------------'
 
     if have_errors:
       for branch in todo:
         if not branch.uploaded:
-          print >>sys.stderr, '[FAILED] %-15s %-15s  (%s)' % (
+          if len(str(branch.error)) <= 30:
+            fmt = ' (%s)'
+          else:
+            fmt = '\n       (%s)'
+          print >>sys.stderr, ('[FAILED] %-15s %-15s' + fmt) % (
                  branch.project.relpath + '/', \
                  branch.name, \
-                 branch.error)
+                 str(branch.error))
       print >>sys.stderr, ''
 
     for branch in todo: