convert: be even more tolerant when detecting svn tags

Former code failed when tracking child directories we assumed were renamed with
their parents but were really created in the tags directory. This happens in
jQuery repository with /tags/ui/1.5b4/release@5455.

hgext/convert/subversion.py

@@ -46,6 +46,9 b' try:'
 except ImportError:
     pass
 
+class SvnPathNotFound(Exception):
+    pass
+
 def geturl(path):
     try:
         return svn.client.url_from_path(svn.core.svn_path_canonicalize(path))
@@ -414,9 +417,15 b' class svn_source(converter_source):'
                         remainings.append([source, sourcerev, tagname])
                         continue
                     # From revision may be fake, get one with changes
-                    tagid = self.latest(source, sourcerev)
-                    if tagid:
-                        tags[tagname] = tagid
+                    try:
+                        tagid = self.latest(source, sourcerev)
+                        if tagid:
+                            tags[tagname] = tagid
+                    except SvnPathNotFound:
+                        # It happens when we are following directories we assumed
+                        # were copied with their parents but were really created
+                        # in the tag directory.
+                        pass
                 pendings = remainings
                 tagspath = srctagspath
 
@@ -474,7 +483,7 b' class svn_source(converter_source):'
         except SubversionException:
             dirent = None
         if not dirent:
-            raise util.Abort('%s not found up to revision %d' % (path, stop))
+            raise SvnPathNotFound(_('%s not found up to revision %d') % (path, stop))
 
         # stat() gives us the previous revision on this line of development, but
         # it might be in *another module*. Fetch the log and detect renames down
@@ -836,7 +845,7 b' class svn_source(converter_source):'
                         latest = self.latest(self.module, firstrevnum - 1)
                         if latest:
                             firstcset.parents.append(latest)
-                except util.Abort:
+                except SvnPathNotFound:
                     pass
         except SubversionException, (inst, num):
             if num == svn.core.SVN_ERR_FS_NO_SUCH_REVISION: