incoming: don't request heads that already are common

Pull would send a getbundle command where common heads were sent both as common
and head, even though there is no reason to request a common head.
The request was thus twice as big as necessary and more likely to hit HTTP
header size limits.

Instead, don't request heads that already are common.

This is fixed in bundlerepo.getremotechanges . It could perhaps also have been
fixed in discovery.findcommonincoming but that would have a bigger impact.

mercurial/bundlerepo.py

@@ -357,6 +357,9 b' def getremotechanges(ui, repo, other, on'
             pass
         return repo, [], other.close
 
+    commonset = set(common)
+    rheads = [x for x in rheads if x not in commonset]
+
     bundle = None
     bundlerepo = None
     localrepo = other.local()

tests/test-setdiscovery.t

@@ -347,7 +347,7 b' Test actual protocol when pulling one ne'
   $ cut -d' ' -f6- access.log | grep -v cmd=known # cmd=known uses random sampling
   "GET /?cmd=capabilities HTTP/1.1" 200 -
   "GET /?cmd=batch HTTP/1.1" 200 - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D513314ca8b3ae4dac8eec56966265b00fcf866db
-  "GET /?cmd=getbundle HTTP/1.1" 200 - x-hgarg-1:common=513314ca8b3ae4dac8eec56966265b00fcf866db&heads=e64a39e7da8b0d54bc63e81169aff001c13b3477+513314ca8b3ae4dac8eec56966265b00fcf866db
+  "GET /?cmd=getbundle HTTP/1.1" 200 - x-hgarg-1:common=513314ca8b3ae4dac8eec56966265b00fcf866db&heads=e64a39e7da8b0d54bc63e81169aff001c13b3477
   $ cat errors.log
 
   $ cd ..

tests/test-treediscovery.t

@@ -508,7 +508,7 b' Both have new stuff in existing named br'
   "GET /?cmd=heads HTTP/1.1" 200 -
   "GET /?cmd=branches HTTP/1.1" 200 - x-hgarg-1:nodes=d8f638ac69e9ae8dea4f09f11d696546a912d961
   "GET /?cmd=between HTTP/1.1" 200 - x-hgarg-1:pairs=d8f638ac69e9ae8dea4f09f11d696546a912d961-d57206cc072a18317c1e381fb60aa31bd3401785
-  "GET /?cmd=changegroupsubset HTTP/1.1" 200 - x-hgarg-1:bases=d8f638ac69e9ae8dea4f09f11d696546a912d961&heads=d8f638ac69e9ae8dea4f09f11d696546a912d961+2c8d5d5ec612be65cdfdeac78b7662ab1696324a
+  "GET /?cmd=changegroupsubset HTTP/1.1" 200 - x-hgarg-1:bases=d8f638ac69e9ae8dea4f09f11d696546a912d961&heads=d8f638ac69e9ae8dea4f09f11d696546a912d961
   "GET /?cmd=capabilities HTTP/1.1" 200 -
   "GET /?cmd=heads HTTP/1.1" 200 -
   "GET /?cmd=branches HTTP/1.1" 200 - x-hgarg-1:nodes=d8f638ac69e9ae8dea4f09f11d696546a912d961