bundle2: refuse empty parameter name

The bundle2 now raise value error when seeing invalid parameter names. The first
introduced rules is: no empty parameter.

The test extension is improve to properly abort when ValueError are encountered.

mercurial/bundle2.py

@@ -45,6 +45,8 b' Binary format is as follow'
   The blob contains a space separated list of parameters. parameter with value
   are stored in the form `<name>=<value>`. Both name and value are urlquoted.
 
+  Empty name are obviously forbidden.
+
   Stream parameters use a simple textual format for two main reasons:
 
   - Stream level parameters should remains simple and we want to discourage any
@@ -54,7 +56,6 b' Binary format is as follow'
 
   Any Applicative level options MUST go into a bundle2 part instead.
 
-
 Payload part
 ------------------------
 
@@ -97,6 +98,8 b' class bundle20(object):'
 
     def addparam(self, name, value=None):
         """add a stream level parameter"""
+        if not name:
+            raise ValueError('empty parameter name')
         self._params.append((name, value))
 
     def getchunks(self):

tests/test-bundle2.t

@@ -10,6 +10,7 b' Create an extension to test bundle2 API'
   > 
   > import sys
   > from mercurial import cmdutil
+  > from mercurial import util
   > from mercurial import bundle2
   > cmdtable = {}
   > command = cmdutil.command(cmdtable)
@@ -22,7 +23,10 b' Create an extension to test bundle2 API'
   >     bundler = bundle2.bundle20()
   >     for p in opts['param']:
   >         p = p.split('=', 1)
+  >         try:
   >         bundler.addparam(*p)
+  >         except ValueError, exc:
+  >             raise util.Abort('%s' % exc)
   > 
   >     for chunk in bundler.getchunks():
   >         ui.write(chunk)
@@ -149,3 +153,12 b' Test unbundling'
       babar%#==tutu
   - simple
   parts count:   0
+
+Test buggy input
+---------------------------------------------------
+
+empty parameter name
+
+  $ hg bundle2 --param '' --quiet
+  abort: empty parameter name
+  [255]