fix #632.

pisi/version.py

@@ -50,6 +50,13 @@ class VersionItem:
 
     def __init__(self, itemstring):
 
+        # special-case: 1.5p
+        # here "p" comes as a separate itemstring and conflicts with
+        # keyword "p". But keyword should allways contain an integer prefix.
+        # So, skipping looking for keywords if the length() is 1 makes the
+        # trick.
+        if len(itemstring) > 1:
+
             for keyword in keywords.keys():
                 if itemstring.startswith(keyword):