bundlespec: rationalize the way we specify stream bundle version

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.

--- a/mercurial/bundle2.py	Tue Apr 02 17:02:39 2024 +0200
+++ b/mercurial/bundle2.py	Tue Apr 02 21:53:17 2024 +0200
@@ -1728,9 +1728,10 @@
     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 @@
     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):

--- a/mercurial/bundlecaches.py	Tue Apr 02 17:02:39 2024 +0200
+++ b/mercurial/bundlecaches.py	Tue Apr 02 21:53:17 2024 +0200
@@ -136,7 +136,7 @@
         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'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 @@
     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