archive: make it work with svn subrepos (issue3308)

- _svncommand() in files() returns a tuple since 0ae98cd2a83f not a string.
- _svncommand() in filedata() returns a tuple not a string.
- "svn list" returns files but also directories.
- "svn list" is not recursive by default.

I have no idea what happens to svn:externals possibly embedded in the svn
subrepository.

mercurial/subrepo.py

@@ -740,12 +740,21 b' class svnsubrepo(abstractsubrepo):'
         return True
 
     def files(self):
-        output = self._svncommand(['list'])
-        # This works because svn forbids \n in filenames.
-        return output.splitlines()
+        output = self._svncommand(['list', '--recursive', '--xml'])[0]
+        doc = xml.dom.minidom.parseString(output)
+        paths = []
+        for e in doc.getElementsByTagName('entry'):
+            kind = str(e.getAttribute('kind'))
+            if kind != 'file':
+                continue
+            name = ''.join(c.data for c
+                           in e.getElementsByTagName('name')[0].childNodes
+                           if c.nodeType == c.TEXT_NODE)
+            paths.append(name)
+        return paths
 
     def filedata(self, name):
-        return self._svncommand(['cat'], name)
+        return self._svncommand(['cat'], name)[0]
 
 
 class gitsubrepo(abstractsubrepo):

tests/test-subrepo-svn.t

@@ -543,3 +543,16 b' First, create that condition in the repo'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ test -f recreated/somethingold
 
+Test archive
+
+  $ hg archive -S ../archive-all --debug
+  archiving: 0/2 files (0.00%)
+  archiving: .hgsub 1/2 files (50.00%)
+  archiving: .hgsubstate 2/2 files (100.00%)
+  archiving (obstruct): 0/1 files (0.00%)
+  archiving (obstruct): 1/1 files (100.00%)
+  archiving (s): 0/2 files (0.00%)
+  archiving (s): 1/2 files (50.00%)
+  archiving (s): 2/2 files (100.00%)
+  archiving (recreated): 0/1 files (0.00%)
+  archiving (recreated): 1/1 files (100.00%)