[Request] [++- ] D11882: rhg: fix a crash on non-generaldelta revlogs
aalekseyev (Arseniy Alekseyev)
phabricator at mercurial-scm.org
Tue Dec 7 18:58:33 UTC 2021
aalekseyev created this revision.
Herald added a reviewer: hg-reviewers.
Herald added a subscriber: mercurial-patches.
REPOSITORY
rHG Mercurial
BRANCH
stable
REVISION DETAIL
https://phab.mercurial-scm.org/D11882
AFFECTED FILES
rust/hg-core/src/revlog/index.rs
rust/hg-core/src/revlog/revlog.rs
tests/test-rhg-no-generaldelta.t
CHANGE DETAILS
diff --git a/tests/test-rhg-no-generaldelta.t b/tests/test-rhg-no-generaldelta.t
--- a/tests/test-rhg-no-generaldelta.t
+++ b/tests/test-rhg-no-generaldelta.t
@@ -22,9 +22,7 @@
1 1 2 0 prev 14 143 93 0.65035 93 0 0.00000
2 1 3 1 prev 12 141 105 0.74468 105 0 0.00000
-rhg breaks on non-generaldelta revlogs:
+rhg works on non-generaldelta revlogs:
$ $NO_FALLBACK hg cat f -r . | f --sha256 --size
- abort: corrupted revlog (rhg !)
- size=0, sha256=e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 (rhg !)
- size=141, sha256=1a7fe778e33d64d5e14a9a126b77038b328356e67bacf308797bc0e39bf204f3 (no-rhg !)
+ size=141, sha256=1a7fe778e33d64d5e14a9a126b77038b328356e67bacf308797bc0e39bf204f3
diff --git a/rust/hg-core/src/revlog/revlog.rs b/rust/hg-core/src/revlog/revlog.rs
--- a/rust/hg-core/src/revlog/revlog.rs
+++ b/rust/hg-core/src/revlog/revlog.rs
@@ -191,11 +191,20 @@
// Todo return -> Cow
let mut entry = self.get_entry(rev)?;
let mut delta_chain = vec![];
- while let Some(base_rev) = entry.base_rev {
- delta_chain.push(entry);
- entry = self
- .get_entry(base_rev)
- .map_err(|_| RevlogError::corrupted())?;
+
+ if self.index.uses_generaldelta() {
+ while let Some(base_rev) = entry.base_rev_or_base_of_delta_chain {
+ delta_chain.push(entry);
+ entry = self.get_entry_internal(base_rev)?;
+ }
+ } else {
+ if let Some(base_rev) = entry.base_rev_or_base_of_delta_chain {
+ delta_chain.push(entry);
+ entry = self.get_entry_internal(base_rev)?;
+ for rev in (base_rev + 1..rev).rev() {
+ delta_chain.push(self.get_entry_internal(rev)?);
+ }
+ }
}
// TODO do not look twice in the index
@@ -291,14 +300,26 @@
bytes: data,
compressed_len: index_entry.compressed_len(),
uncompressed_len: index_entry.uncompressed_len(),
- base_rev: if index_entry.base_revision() == rev {
+ base_rev_or_base_of_delta_chain: if index_entry
+ .base_revision_or_base_of_delta_chain()
+ == rev
+ {
None
} else {
- Some(index_entry.base_revision())
+ Some(index_entry.base_revision_or_base_of_delta_chain())
},
};
Ok(entry)
}
+
+ // when resolving internal references within revlog, any errors
+ // should be reported as corruption, instead of e.g. "invalid revision"
+ fn get_entry_internal(
+ &self,
+ rev: Revision,
+ ) -> Result<RevlogEntry, RevlogError> {
+ return self.get_entry(rev).map_err(|_| RevlogError::corrupted());
+ }
}
/// The revlog entry's bytes and the necessary informations to extract
@@ -309,7 +330,7 @@
bytes: &'a [u8],
compressed_len: usize,
uncompressed_len: usize,
- base_rev: Option<Revision>,
+ base_rev_or_base_of_delta_chain: Option<Revision>,
}
impl<'a> RevlogEntry<'a> {
@@ -375,7 +396,7 @@
/// Tell if the entry is a snapshot or a delta
/// (influences on decompression).
fn is_delta(&self) -> bool {
- self.base_rev.is_some()
+ self.base_rev_or_base_of_delta_chain.is_some()
}
}
diff --git a/rust/hg-core/src/revlog/index.rs b/rust/hg-core/src/revlog/index.rs
--- a/rust/hg-core/src/revlog/index.rs
+++ b/rust/hg-core/src/revlog/index.rs
@@ -85,6 +85,7 @@
/// Offsets of starts of index blocks.
/// Only needed when the index is interleaved with data.
offsets: Option<Vec<usize>>,
+ uses_generaldelta: bool,
}
impl Index {
@@ -101,6 +102,11 @@
return Err(HgError::corrupted("unsupported revlog version"));
}
+ // This is only correct because we know version is REVLOGV1.
+ // In v2 we always use generaldelta, while in v0 we never use
+ // generaldelta. Similar for [is_inline] (it's only used in v1).
+ let uses_generaldelta = header.format_flags().uses_generaldelta();
+
if header.format_flags().is_inline() {
let mut offset: usize = 0;
let mut offsets = Vec::new();
@@ -120,6 +126,7 @@
Ok(Self {
bytes,
offsets: Some(offsets),
+ uses_generaldelta,
})
} else {
Err(HgError::corrupted("unexpected inline revlog length")
@@ -129,11 +136,17 @@
Ok(Self {
bytes,
offsets: None,
+ uses_generaldelta,
})
}
}
/// Value of the inline flag.
+ pub fn uses_generaldelta(&self) -> bool {
+ self.uses_generaldelta
+ }
+
+ /// Value of the inline flag.
pub fn is_inline(&self) -> bool {
self.offsets.is_some()
}
@@ -260,7 +273,7 @@
}
/// Return the revision upon which the data has been derived.
- pub fn base_revision(&self) -> Revision {
+ pub fn base_revision_or_base_of_delta_chain(&self) -> Revision {
// TODO Maybe return an Option when base_revision == rev?
// Requires to add rev to IndexEntry
@@ -298,7 +311,7 @@
offset: usize,
compressed_len: usize,
uncompressed_len: usize,
- base_revision: Revision,
+ base_revision_or_base_of_delta_chain: Revision,
}
#[cfg(test)]
@@ -312,7 +325,7 @@
offset: 0,
compressed_len: 0,
uncompressed_len: 0,
- base_revision: 0,
+ base_revision_or_base_of_delta_chain: 0,
}
}
@@ -351,8 +364,11 @@
self
}
- pub fn with_base_revision(&mut self, value: Revision) -> &mut Self {
- self.base_revision = value;
+ pub fn with_base_revision_or_base_of_delta_chain(
+ &mut self,
+ value: Revision,
+ ) -> &mut Self {
+ self.base_revision_or_base_of_delta_chain = value;
self
}
@@ -375,7 +391,9 @@
bytes.extend(&[0u8; 2]); // Revision flags.
bytes.extend(&(self.compressed_len as u32).to_be_bytes());
bytes.extend(&(self.uncompressed_len as u32).to_be_bytes());
- bytes.extend(&self.base_revision.to_be_bytes());
+ bytes.extend(
+ &self.base_revision_or_base_of_delta_chain.to_be_bytes(),
+ );
bytes
}
}
@@ -458,14 +476,16 @@
}
#[test]
- fn test_base_revision() {
- let bytes = IndexEntryBuilder::new().with_base_revision(1).build();
+ fn test_base_revision_or_base_of_delta_chain() {
+ let bytes = IndexEntryBuilder::new()
+ .with_base_revision_or_base_of_delta_chain(1)
+ .build();
let entry = IndexEntry {
bytes: &bytes,
offset_override: None,
};
- assert_eq!(entry.base_revision(), 1)
+ assert_eq!(entry.base_revision_or_base_of_delta_chain(), 1)
}
}
To: aalekseyev, #hg-reviewers
Cc: mercurial-patches, mercurial-devel
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