zenstore bug-fixes from static analysis pass (#815)

**Bug fixes across zenstore, zenremotestore, and related subsystems, primarily surfaced by static analysis.**

## Cache subsystem (cachedisklayer.cpp)

- Fixed tombstone scoping bug: tombstone flag and missing entry were recorded outside the block where data was removed, causing non-missing entries to be incorrectly tombstoned
- Fixed use-after-overwrite: `RemoveMemCachedData`/`RemoveMetaData` were called after `Payload` was overwritten on cache put, leaking stale data
- Fixed incorrect retry sleep formula (`100 - (3 - RetriesLeft) * 100` always produced the same or negative value; corrected to `(3 - RetriesLeft) * 100`)
- Fixed broken `break` missing from sidecar file read loop, causing reads past valid data
- Fixed missing format argument in three `ZEN_WARN`/`ZEN_ERROR` log calls (format string had `{}` placeholders with no corresponding argument, or vice versa)
- Fixed elapsed timer being accumulated inside the wrong scope in `HandleRpcGetCacheRecords`
- Fixed test asserting against unserialized `RecordPolicy` instead of the deserialized `Loaded` copy
- Initialized `AbortFlag`/`PauseFlag` atomics at declaration (UB if read before first write)

## Build store (buildstore.cpp / buildstore.h)

- Fixed wrong variable used in warning log: used loop index `ResultIndex` instead of `Index`/`MetaLocationResultIndexes[Index]`, logging wrong hash values
- Fixed `sizeof(AccessTimesHeader)` used instead of `sizeof(AccessTimeRecord)` when advancing write offset, corrupting the access times file if the sizes differ
- Initialized `m_LastAccessTimeUpdateCount` atomic member (was uninitialized)
- Changed map iteration loops to use `const auto&` to avoid unnecessary copies

## Project store (projectstore.cpp / projectstore.h)

- Fixed wrong iterator dereferenced in `IterateChunks`: used `ChunkIt->second` (from a different map lookup) instead of `MetaIt->second`
- Fixed wrong assert variable: `Sizes[Index]` should be `RawSizes[Index]`
- Fixed `MakeTombstone`/`IsTombstone` inconsistency: `MakeTombstone` was zeroing `OpLsn` but `IsTombstone` checks `OpLsn.Number != 0`; tombstone creation now preserves `OpLsn`
- Fixed uninitialized `InvalidEntries` counter
- Fixed format string mismatch in warning log
- Initialized `AbortFlag`/`PauseFlag` atomics; changed map iteration to `const auto&`

## Workspaces (workspaces.cpp)

- Fixed missing alias registration when a workspace share is updated: alias was deleted but never re-inserted
- Fixed integer overflow in range clamping: `(RequestedOffset + RequestedSize) > Size` could wrap; corrected to `RequestedSize > Size - RequestedOffset`
- Changed map iteration loops to `const auto&`

## CAS subsystem (cas.cpp, caslog.cpp, compactcas.cpp, filecas.cpp)

- Fixed `IterateChunks` passing original `Payload` buffer instead of the modified `Chunk` buffer (content type was set on the copy but the original was sent to the callback)
- Fixed invalid `std::future::get()` call on default-constructed futures
- Fixed sign-comparison in `CasLogFile::Replay` loop (`int i` vs `size_t`)
- Changed `CasLogFile::IsValid` and `Open` to take `const std::filesystem::path&` instead of by value
- Fixed format string in `~CasContainerStrategy` error log

## Remote store (zenremotestore)

- Fixed `FolderContent::operator==` always returning true: loop variable `PathCount` was initialized to 0 instead of `Paths.size()`
- Fixed `GetChunkIndexForRawHash` looking up from wrong map (`RawHashToSequenceIndex` instead of `ChunkHashToChunkIndex`)
- Fixed double-counted `UniqueSequencesFound` stat (incremented in both branches of an if/else)
- Fixed `RawSize` sentinel value truncation: `(uint32_t)-1` assigned to a `uint64_t` field; corrected to `(uint64_t)-1`
- Initialized uninitialized atomic and struct members across `buildstorageoperations.h`, `chunkblock.h`, and `remoteprojectstore.h`

1 files changed, 7 insertions, 4 deletions

diff --git a/src/zenstore/cas.cpp b/src/zenstore/cas.cpp
index f80952322..8855c87d8 100644
--- a/src/zenstore/cas.cpp
+++ b/src/zenstore/cas.cpp
@@ -153,7 +153,10 @@ CasImpl::Initialize(const CidStoreConfiguration& InConfig)
 		}
 		for (std::future<void>& Result : Work)
 		{
-			Result.get();
+			if (Result.valid())
+			{
+				Result.get();
+			}
 		}
 	}
 }
@@ -426,7 +429,7 @@ CasImpl::IterateChunks(std::span<IoHash>												 DecompressedIds,
 			[&](size_t Index, const IoBuffer& Payload) {
 				IoBuffer Chunk(Payload);
 				Chunk.SetContentType(ZenContentType::kCompressedBinary);
-				return AsyncCallback(Index, Payload);
+				return AsyncCallback(Index, Chunk);
 			},
 			OptionalWorkerPool,
 			LargeSizeLimit == 0 ? m_Config.HugeValueThreshold : Min(LargeSizeLimit, m_Config.HugeValueThreshold)))
@@ -439,7 +442,7 @@ CasImpl::IterateChunks(std::span<IoHash>												 DecompressedIds,
 			[&](size_t Index, const IoBuffer& Payload) {
 				IoBuffer Chunk(Payload);
 				Chunk.SetContentType(ZenContentType::kCompressedBinary);
-				return AsyncCallback(Index, Payload);
+				return AsyncCallback(Index, Chunk);
 			},
 			OptionalWorkerPool,
 			LargeSizeLimit == 0 ? m_Config.TinyValueThreshold : Min(LargeSizeLimit, m_Config.TinyValueThreshold)))
@@ -452,7 +455,7 @@ CasImpl::IterateChunks(std::span<IoHash>												 DecompressedIds,
 			[&](size_t Index, const IoBuffer& Payload) {
 				IoBuffer Chunk(Payload);
 				Chunk.SetContentType(ZenContentType::kCompressedBinary);
-				return AsyncCallback(Index, Payload);
+				return AsyncCallback(Index, Chunk);
 			},
 			OptionalWorkerPool))
 	{