diff --git a/mercurial/obsolete.py b/mercurial/obsolete.py
--- a/mercurial/obsolete.py
+++ b/mercurial/obsolete.py
@@ -275,7 +275,7 @@
     d = {}
     for l in data.split('\0'):
         if l:
-            key, value = l.split(':')
+            key, value = l.split(':', 1)
             d[key] = value
     return d