test-clonebundles.t: add test for incremental pull

This demonstrates issue4932.

tests/test-clonebundles.t

@@ -156,6 +156,31 b' changes. If this output changes, we coul'
   adding file changes
   added 1 changesets with 1 changes to 1 files
 
+Incremental pull doesn't fetch bundle
+
+  $ hg clone -r 53245c60e682 -U http://localhost:$HGPORT partial-clone
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files
+
+  $ cd partial-clone
+  $ hg pull
+  pulling from http://localhost:$HGPORT/
+  applying clone bundle from http://localhost:$HGPORT1/partial.hg
+  adding changesets
+  adding manifests
+  adding file changes
+  added 0 changesets with 0 changes to 1 files
+  finished applying clone bundle
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files
+  (run 'hg update' to get a working copy)
+  $ cd ..
+
 Bundle with full content works
 
   $ hg -R server bundle --type gzip-v2 --base null -r tip full.hg