diff --git a/mercurial/bundle2.py b/mercurial/bundle2.py
--- a/mercurial/bundle2.py
+++ b/mercurial/bundle2.py
@@ -1591,6 +1591,7 @@ def _addpartsfromopts(ui, repo, bundler,
         part.addparam('targetphase', '%d' % phases.secret, mandatory=False)
 
     addparttagsfnodescache(repo, bundler, outgoing)
+    addpartrevbranchcache(repo, bundler, outgoing)
 
     if opts.get('obsolescence', False):
         obsmarkers = repo.obsstore.relevantmarkers(outgoing.missing)
diff --git a/tests/test-bundle-phases.t b/tests/test-bundle-phases.t
--- a/tests/test-bundle-phases.t
+++ b/tests/test-bundle-phases.t
@@ -42,6 +42,7 @@ Phases are restored when unbundling
       26805aba1e600a82e93661149f2313866a221a7b
       f585351a92f85104bff7c284233c338b10eb1df7
       9bc730a19041f9ec7cb33c626e811aa233efb18c
+  cache:rev-branch-cache -- {}
   phase-heads -- {}
       26805aba1e600a82e93661149f2313866a221a7b draft
   $ hg strip --no-backup C
@@ -233,6 +234,7 @@ Restore bundle of entire repo
       dc0947a82db884575bb76ea10ac97b08536bfa03
       4e4f9194f9f181c57f62e823e8bdfa46ab9e4ff4
       03ca77807e919db8807c3749086dc36fb478cac0
+  cache:rev-branch-cache -- {}
   phase-heads -- {}
       dc0947a82db884575bb76ea10ac97b08536bfa03 public
       03ca77807e919db8807c3749086dc36fb478cac0 draft
@@ -258,6 +260,7 @@ Restore bundle of entire repo
   changegroup -- {nbchanges: 2, targetphase: 2, version: 02}
       112478962961147124edd43549aedd1a335e44bf
       4e4f9194f9f181c57f62e823e8bdfa46ab9e4ff4
+  cache:rev-branch-cache -- {}
   phase-heads -- {}
   $ rm bundle
 
@@ -269,6 +272,7 @@ Restore bundle of entire repo
       112478962961147124edd43549aedd1a335e44bf
       dc0947a82db884575bb76ea10ac97b08536bfa03
       4e4f9194f9f181c57f62e823e8bdfa46ab9e4ff4
+  cache:rev-branch-cache -- {}
   phase-heads -- {}
       dc0947a82db884575bb76ea10ac97b08536bfa03 public
   $ rm bundle
@@ -280,6 +284,7 @@ Restore bundle of entire repo
   changegroup -- {nbchanges: 2, targetphase: 2, version: 02}
       4e4f9194f9f181c57f62e823e8bdfa46ab9e4ff4
       03ca77807e919db8807c3749086dc36fb478cac0
+  cache:rev-branch-cache -- {}
   phase-heads -- {}
       03ca77807e919db8807c3749086dc36fb478cac0 draft
   $ rm bundle
diff --git a/tests/test-bundle-type.t b/tests/test-bundle-type.t
--- a/tests/test-bundle-type.t
+++ b/tests/test-bundle-type.t
@@ -76,6 +76,7 @@ test bundle types
   Stream params: {}
   changegroup -- {nbchanges: 1, version: 02}
       c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
+  cache:rev-branch-cache -- {}
   none-v2
   
   % test bundle type bzip2
@@ -85,6 +86,7 @@ test bundle types
   Stream params: {Compression: BZ}
   changegroup -- {nbchanges: 1, version: 02}
       c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
+  cache:rev-branch-cache -- {}
   bzip2-v2
   
   % test bundle type gzip
@@ -94,6 +96,7 @@ test bundle types
   Stream params: {Compression: GZ}
   changegroup -- {nbchanges: 1, version: 02}
       c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
+  cache:rev-branch-cache -- {}
   gzip-v2
   
   % test bundle type none-v2
@@ -103,6 +106,7 @@ test bundle types
   Stream params: {}
   changegroup -- {nbchanges: 1, version: 02}
       c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
+  cache:rev-branch-cache -- {}
   none-v2
   
   % test bundle type v2
@@ -112,6 +116,7 @@ test bundle types
   Stream params: {Compression: BZ}
   changegroup -- {nbchanges: 1, version: 02}
       c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
+  cache:rev-branch-cache -- {}
   bzip2-v2
   
   % test bundle type v1
@@ -150,12 +155,12 @@ Compression level can be adjusted for bu
   $ hg bundle -a -t gzip-v2 gzip-v2.hg
   1 changesets found
   $ f --size gzip-v2.hg
-  gzip-v2.hg: size=427
+  gzip-v2.hg: size=468
 
   $ hg --config experimental.bundlecomplevel=1 bundle -a -t gzip-v2 gzip-v2-level1.hg
   1 changesets found
   $ f --size gzip-v2-level1.hg
-  gzip-v2-level1.hg: size=435
+  gzip-v2-level1.hg: size=475
 
   $ cd ..
 
@@ -171,6 +176,7 @@ Compression level can be adjusted for bu
   Stream params: {Compression: ZS}
   changegroup -- {nbchanges: 1, version: 02}
       c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
+  cache:rev-branch-cache -- {}
   zstd-v2
   
   % test bundle type zstd-v2
@@ -180,6 +186,7 @@ Compression level can be adjusted for bu
   Stream params: {Compression: ZS}
   changegroup -- {nbchanges: 1, version: 02}
       c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
+  cache:rev-branch-cache -- {}
   zstd-v2
   
 
diff --git a/tests/test-bundle.t b/tests/test-bundle.t
--- a/tests/test-bundle.t
+++ b/tests/test-bundle.t
@@ -774,7 +774,7 @@ bundle single branch
   list of changesets:
   1a38c1b849e8b70c756d2d80b0b9a3ac0b7ea11a
   057f4db07f61970e1c11e83be79e9d08adc4dc31
-  bundle2-output-bundle: "HG20", (1 params) 1 parts total
+  bundle2-output-bundle: "HG20", (1 params) 2 parts total
   bundle2-output-part: "changegroup" (params: 1 mandatory 1 advisory) streamed payload
   bundling: 1/2 changesets (50.00%)
   bundling: 2/2 changesets (100.00%)
@@ -783,6 +783,7 @@ bundle single branch
   bundling: b 1/3 files (33.33%)
   bundling: b1 2/3 files (66.67%)
   bundling: x 3/3 files (100.00%)
+  bundle2-output-part: "cache:rev-branch-cache" streamed payload
 
 == Test for issue3441
 
diff --git a/tests/test-clonebundles.t b/tests/test-clonebundles.t
--- a/tests/test-clonebundles.t
+++ b/tests/test-clonebundles.t
@@ -163,7 +163,7 @@ changes, clone bundles produced by new M
 by old clients.
 
   $ f --size --hexdump full.hg
-  full.hg: size=396
+  full.hg: size=442
   0000: 48 47 32 30 00 00 00 0e 43 6f 6d 70 72 65 73 73 |HG20....Compress|
   0010: 69 6f 6e 3d 47 5a 78 9c 63 60 60 d0 e4 76 f6 70 |ion=GZx.c``..v.p|
   0020: f4 73 77 75 0f f2 0f 0d 60 00 02 46 46 76 26 4e |.swu....`..FFv&N|
@@ -188,7 +188,10 @@ by old clients.
   0150: 88 75 34 36 75 04 82 55 17 14 36 a4 38 10 04 d8 |.u46u..U..6.8...|
   0160: 21 01 9a b1 83 f7 e9 45 8b d2 56 c7 a3 1f 82 52 |!......E..V....R|
   0170: d7 8a 78 ed fc d5 76 f1 36 25 81 89 c7 ad ec 90 |..x...v.6%......|
-  0180: 54 47 75 2b 89 49 b1 00 d2 8a eb 92             |TGu+.I......|
+  0180: 54 47 75 2b 89 48 b1 b2 62 ce 8e ce 1e ae 56 41 |TGu+.H..b.....VA|
+  0190: ae 61 ba 4e 41 8e 7e ce 1e ba 60 01 a0 14 23 58 |.a.NA.~...`...#X|
+  01a0: 81 35 c8 7d 40 cc 04 e2 a4 a4 a6 25 96 e6 94 60 |.5.}@......%...`|
+  01b0: 33 17 5f 54 00 00 01 1b 0a ec                   |3._T......|
 
   $ echo "http://localhost:$HGPORT1/full.hg" > server/.hg/clonebundles.manifest
   $ hg clone -U http://localhost:$HGPORT full-bundle
@@ -529,14 +532,14 @@ Test clone bundle retrieved through bund
   $ cat hg.pid >> $DAEMON_PIDS
 
   $ hg -R server debuglfput gz-a.hg
-  f6eca29e25359f6a92f1ea64527cdcf1b5abe62a
+  14ee2f0b3f1d14aeeb2fe037e09fc295c3cf59f5
 
   $ cat > server/.hg/clonebundles.manifest << EOF
-  > largefile://f6eca29e25359f6a92f1ea64527cdcf1b5abe62a BUNDLESPEC=gzip-v2
+  > largefile://14ee2f0b3f1d14aeeb2fe037e09fc295c3cf59f5 BUNDLESPEC=gzip-v2
   > EOF
 
   $ hg clone -U http://localhost:$HGPORT largefile-provided --traceback
-  applying clone bundle from largefile://f6eca29e25359f6a92f1ea64527cdcf1b5abe62a
+  applying clone bundle from largefile://14ee2f0b3f1d14aeeb2fe037e09fc295c3cf59f5
   adding changesets
   adding manifests
   adding file changes
diff --git a/tests/test-debugbundle.t b/tests/test-debugbundle.t
--- a/tests/test-debugbundle.t
+++ b/tests/test-debugbundle.t
@@ -34,12 +34,14 @@ Terse output:
   changegroup -- {nbchanges: 2, version: 02}
       0e067c57feba1a5694ca4844f05588bb1bf82342
       991a3460af53952d10ec8a295d3d2cc2e5fa9690
+  cache:rev-branch-cache -- {}
 
 Quiet output
 
   $ hg debugbundle --quiet bundle2.hg
   Stream params: {}
   changegroup -- {nbchanges: 2, version: 02}
+  cache:rev-branch-cache -- {}
 
 Verbose output:
 
@@ -78,5 +80,6 @@ Verbose output:
   
       c
       b80de5d138758541c5f05265ad144ab9fa86d1db 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 991a3460af53952d10ec8a295d3d2cc2e5fa9690 0000000000000000000000000000000000000000 0
+  cache:rev-branch-cache -- {}
 
   $ cd ..
diff --git a/tests/test-generaldelta.t b/tests/test-generaldelta.t
--- a/tests/test-generaldelta.t
+++ b/tests/test-generaldelta.t
@@ -159,6 +159,7 @@ Test that strip bundle use bundle2
   Stream params: {Compression: BZ}
   changegroup -- {nbchanges: 1, version: 02}
       1c5d4dc9a8b8d6e1750966d343e94db665e7a1e9
+  cache:rev-branch-cache -- {}
   phase-heads -- {}
       1c5d4dc9a8b8d6e1750966d343e94db665e7a1e9 draft
 
diff --git a/tests/test-obsolete-changeset-exchange.t b/tests/test-obsolete-changeset-exchange.t
--- a/tests/test-obsolete-changeset-exchange.t
+++ b/tests/test-obsolete-changeset-exchange.t
@@ -95,10 +95,12 @@ check-that bundle can contain markers:
   Stream params: {Compression: BZ}
   changegroup -- {nbchanges: 1, version: 02}
       f89bcc95eba5174b1ccc3e33a82e84c96e8338ee
+  cache:rev-branch-cache -- {}
   $ hg debugbundle ../f89bcc95eba5-obs.hg
   Stream params: {Compression: BZ}
   changegroup -- {nbchanges: 1, version: 02}
       f89bcc95eba5174b1ccc3e33a82e84c96e8338ee
+  cache:rev-branch-cache -- {}
   obsmarkers -- {}
       version: 1 (70 bytes)
       9d73aac1b2ed7d53835eaeec212ed41ea47da53a f89bcc95eba5174b1ccc3e33a82e84c96e8338ee 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
diff --git a/tests/test-obsolete.t b/tests/test-obsolete.t
--- a/tests/test-obsolete.t
+++ b/tests/test-obsolete.t
@@ -1427,6 +1427,7 @@ Test ability to pull changeset with loca
   Stream params: {Compression: BZ}
   changegroup -- {nbchanges: 1, version: 02}
       e008cf2834908e5d6b0f792a9d4b0e2272260fb8
+  cache:rev-branch-cache -- {}
   phase-heads -- {}
       e008cf2834908e5d6b0f792a9d4b0e2272260fb8 draft
 
@@ -1468,6 +1469,7 @@ Testing that strip remove markers:
   changegroup -- {nbchanges: 2, version: 02}
       e016b03fd86fcccc54817d120b90b751aaf367d6
       b0551702f918510f01ae838ab03a463054c67b46
+  cache:rev-branch-cache -- {}
   obsmarkers -- {}
       version: 1 (92 bytes)
       e008cf2834908e5d6b0f792a9d4b0e2272260fb8 b0551702f918510f01ae838ab03a463054c67b46 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '8', 'operation': 'amend', 'user': 'test'}
diff --git a/tests/test-patchbomb.t b/tests/test-patchbomb.t
--- a/tests/test-patchbomb.t
+++ b/tests/test-patchbomb.t
@@ -390,14 +390,15 @@ test bundle and description:
   Content-Disposition: attachment; filename="bundle.hg"
   Content-Transfer-Encoding: base64
   
-  SEcyMAAAAA5Db21wcmVzc2lvbj1CWkJaaDkxQVkmU1nYvy2xAAAJf//7vFYQXD1/4H7R09C/470I
-  Ak0E4pe4SIIIgQSgGEQOcLAA5VBKqeppMxTI0YjQNBgQMQDI0GgMhtR6I0GI2p6I0yeSEVT9MiYn
-  qjCYQwCBtARptARgBNDEwAGiDCMA40NGjQaNA0AAAAADIAAAA0BkABktCk6qObVxZ2A/33KHibLr
-  UQ4BwkgcPcmuCUAQZCztIWgR1SpBS6IqbIij4UFwhnnMkElcFTqoucIWbsBPK3l+6c+xYaVBWsJo
-  aT0OV/YAOvLrziifDQMJOMIaaYce9agtI2EwQBAq089UiRU+evFHSLRBT7Wa/D/YBaUtU5ezvtr3
-  6yrIS4Iyp9VWESdWPEi6VjRjdcEY4HvbmDIVEAEVJIUrHNIBx/MmnBBRkw8tSlCQ8ABZxf5ejgBI
-  pP5TSQPLVMYbq1qbBPmWN0LYVlAvRbP4X512kDQZ9y4TQbvoZmhe+54sRsEJ8GW3hMJjERh0NNlg
-  aB+3Cw/4u5IpwoSGxfltiA==
+  SEcyMAAAAA5Db21wcmVzc2lvbj1CWkJaaDkxQVkmU1kHdO0GAAAN////vFcSXL9/8H7R09C/578I
+  Ak0E4pe4SIIIgQSgGEQOcLABGYYNKiaaZGEyYjJhGTTRpiHogxGmTRiGRkNMIwhhPSbQJtpQiJkn
+  poyk9I0PUeoNNNBkeUAHqGgD0Ro0NNBoBoaMagNBoNCpNPUemp6QGmgyaPSGmQxGhkZDQbUaBkHp
+  MhoaANNMhkIyIauvSJPL4aUXjIQemQXkoaqOKqAQDIABsZALnf0yCLAyvmktzDWBCVHO6bb6kCqE
+  ZobVEhmMBjs0oQzekgs6PgZSyII8zy9mmG9To49ZlN6TaX5BxlS7cJiuICUdyjNQPIIdQs1Qqqqk
+  JZ2/BksYcU4HQyssZcpkoMco6gRc888KF9BO7BvuSuIPz7A4crBoaQB+euFU1ilz8yIBBmNBDgRX
+  pVh4zkmPiSKcqRJxcshMqh0vkKlgQDTcOujtdmnMVBZfQiPPemcHm2098VJyHBAOqOwluyIKyG92
+  JAR0CCu9SB5q9DyPHUdc5yB5CurIZHt3GM0dCiQRIN0EAcQNmTYTiHdi6B6Dc/ma0hrmSCQXBzfU
+  BEwthEg0YGaJf4u5IpwoSAO6doMA
   --===============*==-- (glob)
 
 with a specific bundle type
diff --git a/tests/test-rebase-conflicts.t b/tests/test-rebase-conflicts.t
--- a/tests/test-rebase-conflicts.t
+++ b/tests/test-rebase-conflicts.t
@@ -297,8 +297,9 @@ Check that the right ancestors is used w
   list of changesets:
   e31216eec445e44352c5f01588856059466a24c9
   2f2496ddf49d69b5ef23ad8cf9fb2e0e4faf0ac2
-  bundle2-output-bundle: "HG20", (1 params) 2 parts total
+  bundle2-output-bundle: "HG20", (1 params) 3 parts total
   bundle2-output-part: "changegroup" (params: 1 mandatory 1 advisory) streamed payload
+  bundle2-output-part: "cache:rev-branch-cache" streamed payload
   bundle2-output-part: "phase-heads" 24 bytes payload
   saved backup bundle to $TESTTMP/issue4041/.hg/strip-backup/e31216eec445-15f7a814-rebase.hg
   3 changesets found
@@ -306,8 +307,9 @@ Check that the right ancestors is used w
   4c9fbe56a16f30c0d5dcc40ec1a97bbe3325209c
   19c888675e133ab5dff84516926a65672eaf04d9
   2a7f09cac94c7f4b73ebd5cd1a62d3b2e8e336bf
-  bundle2-output-bundle: "HG20", 2 parts total
+  bundle2-output-bundle: "HG20", 3 parts total
   bundle2-output-part: "changegroup" (params: 1 mandatory 1 advisory) streamed payload
+  bundle2-output-part: "cache:rev-branch-cache" streamed payload
   bundle2-output-part: "phase-heads" 24 bytes payload
   adding branch
   bundle2-input-bundle: with-transaction
@@ -321,12 +323,15 @@ Check that the right ancestors is used w
   adding f1.txt revisions
   added 2 changesets with 2 changes to 1 files
   bundle2-input-part: total payload size 1686
+  bundle2-input-part: "cache:rev-branch-cache" supported
+  bundle2-input-part: total payload size 74
   bundle2-input-part: "phase-heads" supported
   bundle2-input-part: total payload size 24
-  bundle2-input-bundle: 1 parts total
+  bundle2-input-bundle: 2 parts total
   updating the branch cache
   invalid branchheads cache (served): tip differs
   rebase completed
+  truncating cache/rbc-revs-v1 to 0
 
 Test minimization of merge conflicts
   $ hg up -q null
diff --git a/tests/test-strip.t b/tests/test-strip.t
--- a/tests/test-strip.t
+++ b/tests/test-strip.t
@@ -214,6 +214,7 @@
   Stream params: {Compression: BZ}
   changegroup -- {nbchanges: 1, version: 02}
       264128213d290d868c54642d13aeaa3675551a78
+  cache:rev-branch-cache -- {}
   phase-heads -- {}
       264128213d290d868c54642d13aeaa3675551a78 draft
   $ hg pull .hg/strip-backup/*
@@ -843,13 +844,13 @@ check strip behavior
   list of changesets:
   6625a516847449b6f0fa3737b9ba56e9f0f3032c
   d8db9d1372214336d2b5570f20ee468d2c72fa8b
-  bundle2-output-bundle: "HG20", (1 params) 2 parts total
+  bundle2-output-bundle: "HG20", (1 params) 3 parts total
   bundle2-output-part: "changegroup" (params: 1 mandatory 1 advisory) streamed payload
+  bundle2-output-part: "cache:rev-branch-cache" streamed payload
   bundle2-output-part: "phase-heads" 24 bytes payload
   saved backup bundle to $TESTTMP/issue4736/.hg/strip-backup/6625a5168474-345bb43d-backup.hg
   updating the branch cache
   invalid branchheads cache (served): tip differs
-  truncating cache/rbc-revs-v1 to 24
   $ hg log -G
   o  changeset:   2:5c51d8d6557d
   |  tag:         tip
diff --git a/tests/test-tags.t b/tests/test-tags.t
--- a/tests/test-tags.t
+++ b/tests/test-tags.t
@@ -729,6 +729,7 @@ Check that the bundle includes cache dat
       f63cc8fe54e4d326f8d692805d70e092f851ddb1
       40f0358cb314c824a5929ee527308d90e023bc10
   hgtagsfnodes -- {}
+  cache:rev-branch-cache -- {}
 
 Check that local clone includes cache data