wireproto: correctly escape batched args and responses (issue4739)
This issue appears to be as old as wireproto batching itself: I can
reproduce the failure as far back as 08ef6b5f3715 trivially by
rebasing the test changes in this patch, which was back in the 1.9
era. I didn't test before that change, because prior to that the
testfile has a different name and I'm lazy.
Note that the test thought it was checking this case, but it actually
wasn't: it put a literal ; in the arg and response for its greet
command, but the mangle/unmangle step defined in the test meant that
instead of "Fo, =;o" going over the wire, "Gp-!><p" went instead,
which doesn't contain any special characters (those being [.=;]) and
thus not exercising the escaping. The test has been updated to use
pre-unmangled special characters, so the request is now "Fo+<:o",
which mangles to "Gp,=;p". I have confirmed that the test fails
without the adjustment to the escaping rules in wireproto.py.
No existing clients of RPC batching were depending on the old behavior
in any way. The only *actual* users of batchable RPCs in core were:
1) largefiles, wherein it batches up many statlfile calls. It sends
hexlified hashes over the wire and gets a 0, 1, or 2 back as a
response. No risk of special characters.
2) setdiscovery, which was using heads() and known(), both of which
communicate via hexlified nodes. Again, no risk of special characters.
Since the escaping functionality has been completely broken since it
was introduced, we know that it has no users. As such, we can change
the escaping mechanism without having to worry about backwards
compatibility issues.
For the curious, this was detected by chance: it happens that the
lz4-compressed text of a test file for remotefilelog compressed to
something containing a ;, which then caused the failure when I moved
remotefilelog to using batching for file content fetching.
http://mercurial.selenic.com/bts/issue672
# 0-2-4
# \ \ \
# 1-3-5
#
# rename in #1, content change in #4.
$ hg init
$ touch 1
$ touch 2
$ hg commit -Am init # 0
adding 1
adding 2
$ hg rename 1 1a
$ hg commit -m rename # 1
$ hg co -C 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo unrelated >> 2
$ hg ci -m unrelated1 # 2
created new head
$ hg merge --debug 1
searching for copies back to rev 1
unmatched files in other:
1a
all copies found (* = to merge, ! = divergent, % = renamed and deleted):
src: '1' -> dst: '1a'
checking for directory renames
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: 81f4b099af3d, local: c64f439569a9+, remote: c12dcd37c90a
1: other deleted -> r
removing 1
1a: remote created -> g
getting 1a
2: remote unchanged -> k
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m merge1 # 3
$ hg co -C 2
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo hello >> 1
$ hg ci -m unrelated2 # 4
created new head
$ hg co -C 3
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge -y --debug 4
searching for copies back to rev 1
unmatched files in local:
1a
all copies found (* = to merge, ! = divergent, % = renamed and deleted):
src: '1' -> dst: '1a' *
checking for directory renames
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: c64f439569a9, local: e327dca35ac8+, remote: 746e9549ea96
preserving 1a for resolve of 1a
1a: local copied/moved from 1 -> m
picked tool 'internal:merge' for 1a (binary False symlink False)
merging 1a and 1 to 1a
my 1a@e327dca35ac8+ other 1@746e9549ea96 ancestor 1@81f4b099af3d
premerge successful
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg co -C 4
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge -y --debug 3
searching for copies back to rev 1
unmatched files in other:
1a
all copies found (* = to merge, ! = divergent, % = renamed and deleted):
src: '1' -> dst: '1a' *
checking for directory renames
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: c64f439569a9, local: 746e9549ea96+, remote: e327dca35ac8
preserving 1 for resolve of 1a
removing 1
1a: remote moved from 1 -> m
picked tool 'internal:merge' for 1a (binary False symlink False)
merging 1 and 1a to 1a
my 1a@746e9549ea96+ other 1a@e327dca35ac8 ancestor 1@81f4b099af3d
premerge successful
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)