bundlespec: rationalize the way we specify stream bundle version

Instead of having weird dedicated option for each version (v2, v3, etc) we
reuse the same "stream" parameters. This is consistent with the ability to
request a stream clone using "none-v2;stream=v2".

This changeset introduce no user visible change, this is pure internal cleaning.

mercurial/bundle2.py

@@ -1728,9 +1728,10 b' def writenewbundle('
     caps = {}
     if opts.get(b'obsolescence', False):
         caps[b'obsmarkers'] = (b'V1',)
-    if opts.get(b'streamv2'):
+    stream_version = opts.get(b'stream', b"")
+    if stream_version == b"v2":
         caps[b'stream'] = [b'v2']
-    elif opts.get(b'streamv3-exp'):
+    elif stream_version == b"v3-exp":
         caps[b'stream'] = [b'v3-exp']
     bundle = bundle20(ui, caps)
     bundle.setcompression(compression, compopts)
@@ -1774,10 +1775,10 b' def _addpartsfromopts(ui, repo, bundler,'
     if repository.REPO_FEATURE_SIDE_DATA in repo.features:
         part.addparam(b'exp-sidedata', b'1')
 
-    if opts.get(b'streamv2', False):
+    if opts.get(b'stream', b"") == b"v2":
         addpartbundlestream2(bundler, repo, stream=True)
 
-    if opts.get(b'streamv3-exp', False):
+    if opts.get(b'stream', b"") == b"v3-exp":
         addpartbundlestream2(bundler, repo, stream=True)
 
     if opts.get(b'tagsfnodescache', True):

mercurial/bundlecaches.py

@@ -136,7 +136,7 b' class bundlespec:'
         b'cg.version': b'02',
         b'obsolescence': False,
         b'phases': False,
-        b"streamv2": True,
+        b"stream": "v2",
         b'tagsfnodescache': False,
         b'revbranchcache': False,
     },
@@ -145,7 +145,7 b' class bundlespec:'
         b'cg.version': b'03',
         b'obsolescence': False,
         b'phases': False,
-        b"streamv3-exp": True,
+        b"stream": "v3-exp",
         b'tagsfnodescache': False,
         b'revbranchcache': False,
     },
@@ -388,10 +388,7 b' def isstreamclonespec(bundlespec):'
     if (
         bundlespec.wirecompression == b'UN'
         and bundlespec.wireversion == b'02'
-        and (
-            bundlespec.contentopts.get(b'streamv2')
-            or bundlespec.contentopts.get(b'streamv3-exp')
-        )
+        and bundlespec.contentopts.get(b'stream', None) in (b"v2", b"v3-exp")
     ):
         return True